chapter 4 - dana 4.pdf · michael n. dana purdue university department of horticulture and...

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Chapter 4____________________________________________________________________________________

Herbaceous Ornamental PlantsMichael N. Dana

Purdue University Department of Horticulture and Landscape Architecture

Learning Objectives

From reading and studying this chapter, you should be able to:

• Understand the categories of herbaceous ornamental landscape plants and their

functions in the landscape.

• Recognize the main plants in each category used in Indiana landscapes.

• Use correct terminology to describe the plants and their culture.

• Establish and manage herbaceous ornamentals.

• Select plants for various landscape situations.

Introductory Comments

The best way to learn the large amount of

specific information in this chapter is to break it

into smaller groups. First learn the categories of

herbaceous ornamentals and how each is used in

the landscape. Then, study the images of the

ANNUAL plants, which are available on the CD,

and learn to associate each picture with the

correct plant name. Once you have mastered the

names and developed your ability to recognize

each plant, then spend some time learning the

size, flower color, light and soil moisture

requirements for each. Repeat the process for

the PERENNIALS, the BULBS, then

ORNAMENTAL GRASSES. Finally, study the

cultural requirements for each group beginning

with the annuals. Each subsequent section on

cultural requirements will build on the one(s)

that preceded it.

Introduction to Herbaceous Ornamentals

This chapter is about those plants that are

commonly grown in the landscape or in gardens.

Their flower and leaf colors, textures and plant

forms add interest to developed sites. The plants

can be grouped by life cycle, but also are

considered here by growth habit.

Herbaceous refers to plants with stems

that do not thicken with age, or become

“woody.” Generally, they die to the ground each

winter, but may remain alive underground. Their

stems are commonly soft and pliable.

An annual is a plant that completes its life

cycle in one growing season. It can grow from a

seed and produce new seeds in one season, after

which time it dies, usually being killed by cold

temperature. Many landscape annuals will

bloom continuously through most of the growing

season

A biennial is a plant that requires two

growing seasons to complete its life cycle. It

grows only stems and leaves the first year, then

following winter dormancy, flowers, produces

seeds, and dies. Biennial flowering periods are

usually short, one to three weeks or so.

Biennials are grouped with annuals because they

require yearly re-planting to assure flowering in

the landscape each year. However, they have

limited bloom periods like perennials.

A perennial is a plant that lives for more

than two growing seasons. A herbaceous

perennial usually dies to the ground each winter

(a few species are evergreen), but the in-ground

part of the plant survives. It may not flower for

one or more years following planting, but once it

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begins flowering, will generally flower every

year. The bloom season may only last a few

days to a few weeks, but some last longer and

some re-bloom late in a season. Life span of

perennials varies from “short-lived” types that

may survive two or three years to those that last

indefinitely.

Hardy bulbs are perennials that form

enlarged, distinctive underground structures.

The structures may be composed of roots, stems,

leaves, or flower buds. They vary from above-

ground plant parts in that they help store food for

the following growing season.

Ornamental grasses are most often

perennials, but may be annuals. They are not

mown regularly like lawn, or turfgrasses, but

have a distinctive grass-like habit. Although

lacking in bright colorful flowers, ornamental

grasses may provide tan-colored “dried

arrangement-like” winter interest. They are

simple to maintain.

Landscape Functions

Annual flowers and foliage plants are

grown to make the landscape or garden colorful.

It may be for pure beauty. Often, annuals are

used as focal points themselves or to help focus

attention on landscape elements such as signs or

entranceways. They may also serve as filler

plants in new plantings of perennials or shrubs

that have large spaces between plants. The

continuous color of annuals can be intermingled

with perennials so that there is continuous color

between bursts of perennial bloom.

Perennials add variety and interest to the

landscape or garden with their colorful flowers,

unique plant forms, varied textures and,

sometimes, showy fruits. Some are “tidy” in

habit and lend themselves to formal planting.

Others have a more “loose” growing habit,

providing a quality of “naturalness” when

planted in informal or ecological compositions.

There are perennials that will tolerate most

growing conditions so with correct plant

selection, they can be used in almost any

landscape location. Perennials can provide

temporary screening, reduce erosion on slopes,

or help emphasize landscape elements. One

limitation to perennial usage is their limited

bloom period compared to annuals. Also, some

perennials die down to the ground at times

during the growing season. For this reason,

perennials are often planted in diverse groups to

provide some flowering interest at all times.

Hardy bulbs are primarily providers of

spring flower color. Some of the best bulb

species bloom in the early spring before most

perennials get going and before it is warm

enough to plant annuals. Other hardy bulbs

bloom in summer and are used like other

perennials.

Ornamental grasses bring distinctive form

and textural interest to the landscape. The

flowers of grasses, while part of the texture and

form of the plant, are not brightly colored. Some

grass plants get very large and are useful for

temporary screening or filling up vacant space.

Smaller grasses may work like groundcovers,

while intermediate size plants can function much

like small shrubs. Grasses can serve as focal

elements. A few grasses change from green in

summer to a tan color in winter, but maintain

their form. This allows them to provide a

landscape function in the dormant season much

as they do during the growing season.

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Fertilizer should be worked into the

planting soil prior to setting plants. Use a

complete, quick-release fertilizer such as 5-10-5

(or equivalent) at a rate of 2 to 4 pounds of

fertilizer per 100 sq. ft. of bed area. Slow release

fertilizer may be used at a slightly higher rate,

and higher cost, but should eliminate the need for

midseason fertilization (see below).

The container growing of annuals is done

primarily in commercially prepared, soilless

growing medium. A fresh mix usually has

fertilizer incorporated. Soilless mixes can be re-

used many years in a container and only require

annual recharge with fertilizer. Use a slow-

release fertilizer at label recommended rate. If

you construct your own container mix, use 1/3rd

loam soil, 1/3rd sphagnum moss peat, and 1/3rd

vermiculite or perlite. Containers must have

drainage holes in the bottom to allow excess

water to drain away. Otherwise, root rot and

poor plant performance is likely.

Planting

Annuals are mainly planted after most

danger of spring frost is past. In Indiana, that is

generally early May in the south to late May in

the north. A notable exception is the pansy

which is quite tolerant of cold weather. Pansies

are often planted in the very early spring as soon

as the ground is workable. Sometimes,

landscape managers even like to take risks by

planting pansies in the fall in hopes that a mild

winter will allow a flower display all winter, or

at least allow them to get a very early start in the

spring!

Plant spacing depends on several factors

including a client’s need for “instant effect,”

transplant size and budget. Be sure to allow

enough room between plants for future growth

and to avoid excessive competition. The goal is

to keep every plant healthy for the entire

growing season.

Annual transplants produced in cell packs

or pots must be removed from their containers at

Culture of Annuals

Annuals - Plant Recognition

Plants Included in This Section

(Plants are listed in alphabetical order by genus)

floss flower or ageratum (Ageratum)

snapdragon (Antirrhinum)

wax begonia or fiberous begonia (Begonia)

impatiens (Impatiens)

morning-glory (Ipomoea)

sweet alyssum (Lobularia)

garden geranium (Pelargonium)

petunia (Petunia)

scarlet sage (Salvia)

creeping zinnia (Sanvitalia)

coleus (Solenostemon)

French marigold (Tagetes)

black-eyed Susan vine (Thunbergia)

pansy (Viola)

common zinnia (Zinnia)

Site Selection

Most annuals grow best in the full sun and

in well-drained soil. Those that are shade tolerant

such as impatiens (Impatiens) and wax begonias

(Begonia) grow well in the shade, but the

majority that require full sun grow weakly and

produce fewer flowers in shade. A slow draining

soil will result in weak roots and poor

performance by most annuals.

Soil Preparation

Soil for growing annuals should be well

drained, and when it is handled, it should be

loose, crumbly, and should not clump together.

Heavy soils usually benefit from the addition of

3" or more of organic material such as sphagnum

moss peat, leaf mold or compost. It should be

applied in the fall or early in the spring and then

thoroughly mixed into the soil. Spade or rototill

to a depth of 8-10 inches. If fall bed preparation

is not possible, try to work the soil at least

several weeks before planting in the spring.

Soil pH should be in the range of 6 to 7. A

soil test will show if it is out of this range. Use

lime or sulfur to raise or lower the pH as directed

by the soil test results.

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planting. Root systems found to be tightly bound

should be gently loosened before planting. In

extreme cases, cutting of some roots may be

desirable to encourage root growth into the

surrounding soil. Plants grown in peat pots can

be planted still in the pot, but be sure to

completely cover the pot with soil or remove any

excess pot material that is above ground. Newly

planted annuals should be thoroughly “watered-

in” immediately. A dilute liquid fertilizer may be

applied.

Some annuals, especially small seedlings,

may benefit from a “pinch” at planting. Pinching

is the removal of the primary growing point

resulting in more branching and flowering.

However, it will usually delay the development

of the first flowers. CAUTION: don’t expect to

pinch all annuals. Some grow tall and erect

naturally and do very little branching, even if

pinched. Often, newer cultivars of annuals

branch more naturally than the older types.

Check first.

Mulch such as compost, shredded bark,

pine needles, etc. may be applied for weed

control, moisture retention and soil cooling.

Avoid mulch deeper than 2 inches and keep the

mulch away from plant stems. One useful

approach is to mulch a bed before planting, then

plant through the mulch. Be sure, though, that

plant roots get placed into the soil, not just in the

mulch.

Management

Irrigation is essential most years in Indiana

to assure top-quality annuals. About 1 inch of

water is needed by most annuals per week. New

transplants should be watered every day or two

for a week, but once plants become established,

irrigation should be limited to a single deep

watering once per week.

Less watering may be possible if water-

holding polymers are used. If added to the soil

when beds are prepared, polymers may retain

enough water near plant roots to extend the time

between waterings to several more days than

usual.

Fertilizer, like that used in bed preparation

(5-10-5), should be applied about six weeks after

transplanting at a rate of 1-2 pounds per 100 sq.

ft. It should be repeated six weeks later. If a

slow-release product was used in bed

preparation, midseason fertilizing may be

omitted.

Deadheading is the removal of spent

flowers. It is useful to improve appearance in

some plants, notably geraniums. It may

promote stronger continued flowering by

eliminating seed production. Some annuals, like

petunias “hide” their spent flowers with new

growth and are not deadheaded.

Some annuals, especially petunias, benefit

from cutting back in the later part of the summer

to promote late season branching, much as

pinching does in the early season.

Weed control is best practiced in annuals

with a combination of hand weeding, mulching

and growth of the annuals themselves to compete

successfully with weeds. Herbicides, especially

those applied after the flowers are planted, but

before any weeds appear (pre-emergence

herbicides) may be useful, but should be used

with knowledge and caution.

Insect pests and diseases can be a problem

in annuals. Regular monitoring of plant health

and quick attention to problems is part of

successful management.

4-5

Perennials - Plant Recognition



northern maidenhair fern (Adiantum)

carpet bugle (Ajuga)

hybrid anemone (Anemone)

long-spurred columbine Aquilegia)

New England aster (Aster)

false spirea or Arend’s hybrid astilbe (Astilbe)

snow-in-summer (Cerastium)

leadwort (Ceratostigma)

clematis (Clematus)

lance-leaf coreopsis (Coreopsis)

threadleaf coreopsis (Coreopsis)

perennial pinks (Dianthus)

purple coneflower (Echinacea)

barrenwort or bishop’s-hat (Epimedium)

perennial blanket flower (Gaillardia)

cranes-bill or true geranium (Geranium)

daylily (Hemerocallis)

coral bells (Heuchera)

hosta or plantain-lily (Hosta)

bearded iris (Iris)

spotted dead-nettle (Lamium)

Shasta daisy (Leucanthemum)

garden lily (Lilium)

creeping lily-turf (Liriope)

bee-balm or bergamot (Monarda)

garden peony (Paeonia)

oriental poppy (Papaver)

Russian sage (Perovskia)

garden phlox (Phlox)

creeping phlox (Phlox)

Christmas fern (Polystichum)

orange coneflower (Rudbeckia)

hybrid perennial salvia (Salvia)

showy stonecrop or showy sedum (Sedum)

barren strawberry (Waldsteinia)

Plant and Site Considerations

Success with perennials requires a

compatible union between the characteristics of

the site and the requirements of the perennial

plant. Also, design functionality of the plant in

the site must be correct. Perennials offer so

much diversity that plants are available for just

about any site. Remember that only perennials

with similar site requirements should be planted

together.

Light level, the degree of shadiness and the

duration of that shade, is fundamental. Shade

may be from a natural source such as trees or

from architectural elements. It may only be for

part of the growing season or may be year round.

Commonly used categories for light level are:

• Full sun - at least six hours of direct sun per

day

• Partial shade - part day direct sun, or all day

filtered shade through high trees

• Full shade - only a few minutes of direct sun

in a day, little filtered light

• Deep shade - no direct sunlight, dense,

continuous overhead canopy - this degree of

shade is unsuitable for all but the most

shade-tolerant perennials

Soil drainage, aeration, and moisture

retention is the other basic consideration.

Certain perennial flowers will grow in standing

water, others in dry gravelly soils. The match is

the key. Check the soil drainage characteristics

before making plant choices.

Winter hardiness is important given

perennials must survive from year to year.

Indiana sits in USDA hardiness zones 5 and 6

with average annual winter low temperatures

ranging from the extremes of about -20 ∫F in the

north to -10∫F in the south

(see:www.usna.usda.gov/Hardzone/

ushzmap.html). Perennials tolerant to colder

temperatures than these will usually survive here,

but those adapted to warmer zones may be killed

over winter. Microclimates near buildings and

special winter protection from mulching may

allow less hardy species to survive.

Summer heat tolerance can also limit a

perennial’s adaptability to a location. For

example, lupines and delphiniums take the cold

of Indiana all right, but are better suited to cooler

summer conditions than are typically found here.

The American Horticultural Society began to

map this effect in the late 1990’s. The AHS

“Plant Heat-Zone Map” may be useful in helping

Culture of Perennials

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determine southern limits to adaptability

(see:www.ahs.org/pdfs/heatmap.pdf).

Disease and insect pest tolerance is an

important aspect of perennial selection. While

most problems can be controlled with enough

management input, the choice of less problem-

prone plants is generally preferred. Planting a

diversity of species tends to lessen such

problems.

The mature size of a perennial is important

to consider. Crowding of a large plant into a

small space can mean the plant is weakened from

lack of resources to grow. It probably also

means the plant is a nuisance functionally,

requiring constant attention to size control. Be

aware of a plant’s size potential before planting.

Perennial flowers require management. To

be at their best, some take very little, while some

a lot. For example, some perennials must have

structural supports to keep them from flopping

over, especially when in bloom. Plant selection

should be tempered by the level of management

that will be provided for the plant.

Site Preparation

Perennials are available to match most soil

conditions. However, it may be desirable to alter

the existing soil conditions to allow the growing

of plants that require a different set of conditions.

And often, plants that will tolerate poorly

drained, tight soils will grow better if provided

with improved soil conditions.

Site preparation for perennials is best done

well ahead of plant establishment. The year

prior to planting is about ideal. It should be done

thoroughly at the beginning given the intent that

perennials should grow for a long time without

replanting.

If a site has an established perennial grass

or other weedy plant cover growing on it, the

weedy plants must be eliminated before

perennial planting. If time permits, repeated

tillage or smothering with organic or plastic

mulch is effective. If time is short, a non-

selective systemic herbicide (for example

Round-UpÆ or FinaleÆ) can be used.

Soil should be worked more deeply for

perennials than annuals, because perennial root

systems may grow many feet into the soil over

many years. Prepared soil depth should be as

deep as practical. It is usually limited to 12" -

18", but even deeper preparation, particularly on

sites with significant soil compaction will pay

long-term benefits.

Slow draining soils usually can be

improved by the addition of liberal amounts of

organic material such as sphagnum moss peat,

leaf mold or compost. Add organic matter

amendments up to one-third by volume. In

extreme cases of poor drainage when plants

requiring good drainage are to be grown,

consider creating a raised bed.

Optimum soil pH for perennials can range

from below 6 to above 7. Be sure there is a good

match between the requirements of the selected

plant species and the soil at the site. Use lime or

sulfur to raise or lower the pH, if needed, as

directed by soil test results.

Fertilizer should be added to the planting

soil as it is worked. A soil test will point out

significant deficiencies. Phosphorus is especially

difficult to add once plants are in place. In the

absence of a soil test report, use a complete

fertilizer such as 10-10-10 (or equivalent) at a

rate of 2 to 6 pounds of fertilizer per 100 sq. ft.

of bed area.

Planting

Planting of perennials is best done in

spring or in late summer to early fall. In Indiana,

that means April to early June and late August

through early October. Planting of perennials is

most often done with container grown plants. In

some cases, especially large commercial

plantings done in early spring, bare-root plants

may be planted.

4-7

When perennials grown in plastic pots are

planted, remove the container completely.

Loosen any tightly bound roots and plant them

into the soil of the new location. If the container

is a bio-degradable fiber pot, cut gashes in the

sides of the pot in 5 or 6 places vertically, tear off

the pot rim that extends above the soil in the pot,

and then plant, pot and all. The finished planting

depth for both pot types should be the same as in

the container.

Bare root plants, because they are dormant,

must be kept cool and moist, not wet, until

planted. Spread the root system fully when

planting and gently place soil completely around

the roots. Firm the soil by hand. Correct

planting depth is very important and varies with

species. For example, the buds on the crown of a

peony should be planted at 2" below soil level.

Iris rhizomes, however, should be planted right at

the soil surface with the roots extending into the

soil below. Always check for proper planting

techniques for the species you’re handling.

Mulch such as compost, shredded bark,

pine needles, etc. may be applied for weed

control, moisture retention and soil cooling.

Avoid mulch deeper than 2 inches and keep the

mulch away from plant stems.

Planting should be followed promptly by

thorough watering. A dilute liquid starter

fertilizer may be included in this irrigation.

Mulching with 1-2 in. of organic mulch material

will reduce weeds during the establishment year.

Management

Irrigation is essential for newly planted

perennials, especially during the early part of the

establishment period. In most years in Indiana, it

is desirable to be able to irrigate perennial

plantings during the driest parts of summer.

However, perennials in particular sites, such as

wet bog gardens or dry rock gardens may not

require any supplemental irrigation.

One or two fertilizations, in spring as

growth commences , meet the needs of most

perennials. The nutrient needs of perennials vary

widely though, so you’ll need to check into

specific plants. On average, one pound of 5-10-5

per 100 sq. ft. used in early spring and again 6-8

weeks later is adequate. Be sure dry granular

fertilizer doesn’t rest on leaves or foliar burn

may result. Wash it off with a light irrigation.

Continued soil building by adding organic

matter should be done in the spring, too.

Annually, add an inch or two of compost or other

organic material along with the fertilizer

described above. Work it in with the top few

inches of soil around each perennial taking care

to disrupt existing roots as little as possible.

Pinching of some perennials in spring

through the end of June can promote branching,

reduce overall plant size and prevent flowering

until fall. Chrysanthemums and asters may be

handled in this manner. Deadheading, or spent

flower removal, may be practiced for aesthetic

reasons, to reduce self-sowing, maintain

compactness, and to promote stronger plant

growth for future years. However, many

perennials produce interesting fruits and dried

flower structures. They may be left on the plants

to be enjoyed long after flowering is past.

An often overlooked aspect of growing

perennials is plant support. Vining plants,

obviously, require support such as a trellis or

fence to grow on. Many other species do not

perform well without supplemental staking to

support weak stems bearing the weight of large

flowers. Staking takes many different forms.

Rough twiggy shoots (from the pruning of

woody plants) can be placed in the ground

extending above some perennial plants in the

early spring. The perennial then grows up

through the twigs hiding them, and the twigs

lend support to the perennial. Wire or twine

frames between stakes can function in a similar

manner. Single stakes and plant ties can be

effective for perennials that have a strong single

stem growth habit. For perennials that tend to

splay open from the center, such as peonies or

false indigo (Baptisia), wire rings and stakes, a

wire grid or linking stake frames are effective.

Weed control is not usually a major

problem in established perennial plantings. Thin

mulching may be used effectively in the first

4-8

year to reduce weed presence. Later, hand

pulling or shallow cultivation is usually

sufficient. Occasionally persistent weeds may

become a problem. Perennial grassy weeds such

as quackgrass, for example, may be controlled

using certain grass-selective herbicides. If a

weed problem becomes bad enough, complete

renovation involving lifting the perennials,

attacking the weeds by hand removal, with non-

selective herbicides or by soil fumigation, and

replanting may be necessary.

Insect pests and diseases can be a problem

in perennials. Regular monitoring of plant health

and quick attention to problems is part of


All perennial plants expand over time.

Eventually, most should be divided. Division

can reduce overcrowding and thus rejuvenate a

planting, reduce the size of a planting, or restart a

plant in its proper location after the center has

died out. Division is done in spring for many

species, and may generally be done in any non-

bloom season. Bearded iris, for example, grow

less actively in mid-summer so that is optimum

timing for their division. Showy stonecrop

(Sedum) blooms in fall, so spring division is best.

Division consists of lifting the crown and

roots of the plant from the soil and separating it

into pieces. Each piece must have functional

crown tissue (usually with buds) attached to

functional roots. The division may be done with

just hands, with one or two digging forks, or may

require a knife or other cutting tool. Each

perennial species divides in its own unique way

so check the proper method for the species you

handle. Re-set the plants at about the same depth

as they were growing prior to lifting. A few may

be set just slightly lower, some a bit higher to

allow for settling of the soil.

There are a few plants that expand so

slowly that division is seldom practiced. This

group includes monkshood (Aconitum), false

indigo (Baptisia), poppies (Papaver), and Lenten

rose (Helleborus).

Transplanting of perennials is sometimes

required as design changes are made or land-

scape conditions evolve and change. Trans-

planting consists of lifting whole plants, intact,

with a large clump of soil adhering to the roots

and replanting immediately. It should be done in

spring or early fall, and should be followed with

thorough watering. If transplanting must be

done in summer, plant tops should be cut back

somewhat to reduce water loss.

After a few hard freezes, the perennial

planting may be cleaned up and dead plant tops

moved off-site or to the compost pile. A short

piece of stem may be left in some cases to mark

plant locations. In this way, late emerging

perennials such as butterfly milkweed

(Asclepias) may be saved from inadvertent

damage.

Once the ground is frozen, but before

severe cold weather occurs, a winter mulch of

several inches of organic material may be useful

in the perennial planting. It can help protect

from frost heaving any perennials that were

planted or transplanted late. Winter mulching

can also help protect marginally hardy species

from the coldest temperatures of winter. Winter

mulches should be pulled away from plants in

early spring before or just as new growth

emerges.

4-9

Hardy Bulbs - Plant Recognition



crocus (Crocus)

common snowdrop (Galanthus)

garden hyacinth (Hyacinthus)

daffodil or narcissus (Narcissus)

tulip (Tulipa)

Most hardy bulbs are spring blooming.

These include the larger plants such as tulips

(Tulipa) and daffodils (Narcissus), and minor

bulbs such as crocus (Crocus) and snowdrops

(Galanthus). The spring blooming bulbs go

dormant during the summer and are not seen

above ground at that time. They require the low

temperature exposure of winter before they will

bloom again. Some hardy bulb species are

summer blooming, such as true lilies (Lilium).

Lilies are often used with other perennials and

their cultural requirements are similar to many

perennials.

Site Selection

Most hardy bulb species require full sun.

However, many spring bloomers complete their

growth period prior to the leaf-out of deciduous

trees in the spring. Thus, a site that is shady in

mid-summer may be suitable for bulbs due to the

high light level in the spring. Lilies need full sun

and, for those that grow very tall, should be

located out of strong winds. Cool soil

temperatures are best for lilies, so mulch or

shade from surrounding plants is desirable.

Soil Preparation

Soil for growing hardy bulbs should be

like that for annuals (see above), except bulbs,

on average, require even better drainage.

Attempting to grow bulbs in soil that retains too

much water will result in bulb rot and death. A

sandy loam is ideal. Consider soil replacement

to improve very poorly drained sites, or make

raised beds. Prepare soil as far in advance of

planting as possible.

Depth of soil preparation should be deeper

than for annuals, to 12" or more. Large bulbs are

often planted 6" below the soil surface and then

need another 6" or more for the roots to penetrate

into the soil below the bulb. Fertilizer should be

worked into the planting soil prior to planting

bulbs. Use a complete fertilizer such as 5-10-10

(or equivalent) at a rate of 2 to 4 pounds of

fertilizer per 100 sq. ft. of bed area.

Planting

Plant only good quality, large bulbs for the

best landscape performance. Bulbs should be

firm and heavy with the tip and basal plate intact.

The surface should be free of substantial injuries

and of even color.

The planting period for hardy bulbs is from

late August until November (or until the ground

freezes). The later the planting, the less time the

plant will have to develop strong roots to support

spring flowering.

Spacing of bulbs depends on desired effect

and budget. High impact is gained with tulips

spaced just 4" apart, but wider spacing can

expand the size of a planting with the same

quantity of bulbs. Daffodils may be spaced more

widely as they will expand over time and need

room to grow before becoming overcrowded. If

bulbs are used with other plants such as among

shrubs or perennials, groups of bulbs are

generally more effective than widely spaced

individual plants.

Bulbs can be planted using a trowel, bulb

planter, or power auger. Pre-determine each bulb

location, excavate, and then place each bulb in

its hole at correct depth (see chart). A handy

rule-of-thumb is to plant bulbs at a depth 2.5-3

times the bulb’s height. Be sure the top of the

bulb (usually some-what pointed) is facing

upward. For mass plantings, an entire bed may

be excavated to proper depth, bulbs placed, and

then covering soil carefully added over the top.

Culture of Hardy Bulbs

4-10

Certain newly planted bulbs in loose

recently-worked soil, and even long established

bulbs can be targets for rodents. Tulips, crocus

and some minor bulbs may be destroyed by the

feeding of chipmunks, squirrels or mice. To help

prevent damage from these pests, lay fine mesh

hardware cloth over bulb beds. This remedy will

not prevent animals from burrowing to deeper

bulbs. Hardware cloth placed in the ground

surrounding such bulbs is effective, but may not

be practical.

Irrigate following planting to settle the soil

around the bulbs. Mulch may be useful following

planting. It should typically be applied after the

ground is frozen to minimize freeze-thaw cycles

that can disrupt newly planted bulbs. In cases

where bulb planting was done very late (i.e.

December), mulch may be useful immediately

following planting to help keep the ground warm

to extend the season for root growth.

Management

The Indiana climate generally provides

adequate moisture for hardy bulbs. If natural

rainfall is below normal amounts during the

spring period of active growth, apply

supplemental water. Flooding or soaker hoses

are better than overhead sprinklers.

A complete fertilizer such as 5-10-10 (or

equivalent) should be applied annually to bulb

plantings as the plants emerge. Application rate

should be 1-2 pounds per 100 sq. ft. with larger

bulbs at the high end, minor bulbs lower.

Deadheading spent flowers before seeds

enlarge is beneficial with the larger bulbs. It is

generally impractical for minor bulbs.

The leaves of hardy bulbs should be

allowed to grow for six weeks or so following

the bloom period. This time is generally

adequate to insure flowering the next year.

During this time, do not bind the leaves together.

To maximize bulb growth, allow leaves to stay

on the plants until they begin to yellow and die

back naturally.

An abundance of foliage with few or no

flowers is an indication that bulbs have become

crowded. Once the foliage dies, the bulbs can be

lifted, divided, and replanted immediately or

stored (70oF, dark and dry) and replanted in fall.

Large bulbs may flower the following year;

small bulbs will reach flowering size in future

years.

Weeds are best controlled in bulb plantings

by starting with a weed-free planting bed,

applying a thin layer of organic mulch in early

winter and hand weeding during the bulb

flowering season. Cultivation and other

measures including herbicides may be useful on

the soil surface above bulbs during the bulb

dormant season.

Insect pests and diseases are seldom a

major problem in hardy bulbs in the landscape.

Regular monitoring of plant health and quick

attention to problems is part of successful

management.

4-11

Ornamental Grasses - Plant Recognition



giant reed (Arundo)

feather reed grass (Calamagrostis)

sedge (Carex)

blue fescue (Festuca)

Chinese silver grass (Miscanthus)

switchgrass (Pennisetum)

perennial fountain grass (Pennisetum)

plume grass (Saccharum)

The best ornamental grasses for use in

Indiana landscapes are perennial, clump-

forming, or “bunch” grasses that spread only

very slowly by tillering. They tend to stay as

individual plants compared to the rhizomatous,

or sod-forming turf grasses that are commonly

used for lawns. Ornamental grasses range from a

few inches to many feet tall and are adapted to a

variety of growing conditions.

Site selection

Almost all grasses require full sun to be at

their best. Some tolerate part-day shade while a

very few grow satisfactorily in consistent light

shade. Protection from the strongest winds is

desirable, but some wind exposure usually

results in a stronger, more “stocky” plant.

Ornamental grass species can be found that will

tolerate soil moisture conditions from con-

tinuously wet to consistently dry. It is critical to

match the plant species choice to its site.

Soil preparation

Grasses are remarkably able to tolerate

most “unimproved” soil conditions. However,

like other perennials, they usually grow more

vigorously and reach larger size if the soil

conditions are favorable. Soil improvement for

ornamental grasses is the same as described for

perennials (see above).

Planting

The spacing of ornamental grasses is

dependent on the desired landscape design effect

and on the need for adequate room to grow to

insure a healthy plant. Grass clumps expand in

size over time so original plant spacing should

allow room for this expansion. Tight spacing

may be desirable in certain cases and inter-plant

competition may slow the rate at which the

clumps expand.

Container plants of varying sizes are the

typical planting-out material for ornamental

grasses. They may be nursery size containers

(one gallon and up) or smaller units such as

quarts or narrow, deep-root tubes. Plants of

named cultivars are commonly produced by

division from parent stock plants. When species

plants are produced, they are commonly grown

from seed.

Planting is best done in spring or in late

summer to early fall. In Indiana, that means

April to early June and late August through early

October. Remove the container completely.

Loosen any tightly bound roots and plant them

into the soil of the new location. If the container

is a bio-degradable fiber pot, cut gashes in the

sides of the pot in 5 or 6 places vertically, tear off

the pot rim that extends above the soil in the pot,

and then plant, pot and all. The finished planting

depth should be the same as in the container.

Planting should be followed promptly by

thorough watering. A dilute liquid starter

fertilizer may be included in this irrigation.

Management

Irrigation is generally not needed in

Indiana for most ornamental grasses except in

the most severe conditions of drought. Wet site

adapted plants are an exception. Grasses may

grow somewhat smaller in a dry year compared

to wetter conditions.

Culture of Ornamental Grasses

4-12

Annual fertilization with a complete

fertilizer such as 10-10-10 (or equivalent) at one

or two pounds per 100 sq. ft. is usually adequate.

Don’t over fertilize. Grasses can become weak

and flop over (lodge) if growth is too fast and

soft.

Once each year, the dead vegetation should

be removed from a grass plant. This is best done

in very early spring, before new growth

commences. Cut just above the crown. The

shoots of some larger grass species can be quite

woody and tenacious. A power hedger, weed

whip, pruning loppers or a chain saw may be

needed. Grasses may be cut back in late fall.

However, any winter effects will be lost this way

and some people suggest this may increase

winter injury.

Periodic division of ornamental grasses is

needed, but the frequency varies greatly among

species. Some, such as feather reed grass

(Calamagrostis) may go many years with little

need for division. Others, like many Japanese

silver grass (Miscanthus) cultivars tend to open

up in the center of the clump after several years.

When dividing, the entire grass clump should be

lifted, then a part of the clump should be reset in

the original planting location. Grass clumps of

some larger species can be woody. Division may

require use of an ax or saw in addition to a

shovel. Do this work in late winter or early

spring.

Ornamental grasses are generally free from

pest problems. Regular monitoring of plant

health and quick attention to problems is part of


4-13

Plant Recognition with Characteristics and Cultural Information

For each herbaceous plant presented in this manual, several images are presented on the

accompanying Indiana Accredited Horticulturist Training Manual CD. Those images correspond with

the Plant Characterisitics and Cultural Information data found in this chapter. The images should be

studied together with the plant names and cultural requirements. The categories of information are

explained below.

Explanation of Plant Data Categories and Their Contents

Common name: One or two often-used common names are given, but there may be others in use in

other areas. Common names may be capitalized or not, but when a proper name is part of a common

name, that part should be capitalized (i.e. French marigold).

Scientific name: This plant name is in a form resembling the language of Latin and is in italics to

indicate that. The first word is the Generic name (genus) and it is capitalized. A descriptive second

word follows (specific epithet). Together the two words make up the species name. In some cases

only a genus is indicated followed by “hybrids” or “species”. This is done when a group of species

or horticultural hybrids are meant, rather than an individual species.

Type: This category describes the plant’s growth form or type. “Flower” indicates a clump or mounded

habit, “Vine” suggests a viney or elongated stem form, “Groundcover” refers to plants that spread

horizontally and low to the ground, “Fern” indicates non-flowering, spore bearing plants.

Plant height (feet): Vertical plant size is specified in feet and may be indicated as a range. An actual

plant’s landscape size will depend on cultivar and cultural conditions. In the case of plants with

flowers that stand significantly above the leaves, Leaves and Flowers are listed separately and the

height of flowers is the total plant height when in bloom.

Flower colors: Major color categories of the flowers on a plant, within which there many be many

different shades of a color. More than one color may occur on a single flower.

Light requirements: This indicates the amount of sunlight needed by the plant for optimal performance.

Full sun - at least six hours of direct sun per day

Partial shade - part day direct sun, or all day filtered shade through high trees

Full shade - only a few minutes of direct sun in a day, little filtered light

Deep shade - no direct sunlight, dense, continuous overhead canopy - unsuitable for most perennials.

Soil moisture requirements: Amount of water needed by the plant for optimal growth performance.

“Moderate” suggests a well-drained soil, but one that holds water for several days following rainfall

or irrigation. “Tolerates Wetness” or “Dryness” indicates those plants that need more or less

frequent irrigation or different soil type that holds water longer or releases it more quickly.

Bloom season: Timing of flowering during the growing season. “Early Spring” suggests March and

April, “Spring” includes May and June, “Summer means June through early September, and “Fall”

means September and October. Precise bloom time depends on geographic location and seasonal

variation.

Winter landscape value: Indicates a quality rating of those plants (especially ornamental grasses) that

retain much of their form into the dormant season even though the above ground plant parts are

dead. Also indicates plants with some evergreen tendency, generally more pronounced in southern

Indiana.

Hardiness Zone: Most northern region where plant can be expected to reliably survive winter

temperatures. Number refers to the zone system on the USDA Plant Hardiness Zone Map. With

extra effort given to winter protection, some plants may be able to survive further north than

indicated. This category is only presented for perennial plants.

Noteworthy species and/or cultivars: If very few cultivars of a plant are dominant in the landscape

industry, cultivars are listed by name with significant characteristics. If the entry includes multiple

species, then significant species are listed by name. Some have too many cultivars to list and for all

annuals, because there are often dozens to hundreds of cultivars with new ones released regularly by

the seed trade, this category is omitted.

4-14

Annuals

Complete Characteristics and Cultural

Information

Remember, plant images are found on the IAH

Training Manual CD.

Common name: floss flower or ageratum

Scientific name: Ageratum houstonianum

Type: Flower

Plant height (feet): 0.5-1.5

Flower colors:Violet Lavender Blue Pink White

Light req.: Full sun Partial shade

Soil moisture req.: Tolerates Dryness Moderate

Common name: snapdragon

Scientific name: Antirrhinum majus

Type: Flower


Flower colors: Yellow Orange Red Pink White


Soil moisture req.: Moderate

Common name: wax begonia or fiberous

begonia

Scientific name: Begonia xsemperflorens-

cultorum

Type: Flower


Flower colors: Red Pink White

Light req.: Full sun Partial shade Full Shade


Common name: impatiens

Scientific name: Impatiens walleriana

Type: Flower


Flower colors: Violet Lavender Orange Red

Pink White

Light req.: Partial shade Full Shade


Common name: morning-glory

Scientific name: Ipomoea purpurea

Type: Vine

Plant height (feet): to 10+

Flower colors: Violet Lavender Blue Yellow

Red Pink White

Light req.: Full sun


Common name: sweet alyssum

Scientific name: Lobularia maritima

Type: Flower

Plant height (feet): 0.3

Flower colors: Violet Lavender Pink White



Common name: garden geranium

Scientific name: Pelargonium x hortorum

Type: Flower


Flower colors: Violet Orange Red Pink White



Common name: petunia

Scientific name: Petunia xhybrida

Type: Flower



Red Pink White


Soil moisture req.: Dry to Moderate

Common name: scarlet sage

Scientific name: Salvia splendens

Type: Flower


Flower colors: Violet Red Pink White



Common name: creeping zinnia

Scientific name: Sanvitalia procumbens

Type: Vine

Plant height (feet): 0.5 trailing to 2.0

Flower colors: Yellow Orange w/Black centers


Soil moisture req.: Dry to Moderate

Common name: coleus

Scientific name: Solenostemon scutellarioides

Type: Flower


Flower colors: Blue White



4-15

Common name: French marigold

Scientific name: Tagetes patula

Type: Flower


Flower colors: Yellow Orange Red Maroon



Common name: black-eyed Susan vine

Scientific name: Thunbergia alata

Type: Vine


Flower colors: Yellow Orange White (some w/

Maroon centers)



Common name: pansy

Scientific name: Viola xwittrockiana

Type: Flower



Orange Red Maroon White


Soil moisture req.: Moderate Tolerates Wetness

Common name: common zinnia

Scientific name: Zinnia elegans

Type: Flower


Perennial


Information


Training Manual CD. A complete explanation of

the categories can be found on page 4-13 of this

chapter.

Common name: northern maidenhair fern

Scientific name: Adiantum pedatum

Type: Fern


Flower colors: N.A.

Bloom season: N.A.

Light req.: Partial shade Full Shade Deep Shade


USDA Hardiness Zone: 4

Noteworthy cultivars: none

Common name: carpet bugle

Scientific name: Ajuga reptans

Type: Groundcover


Flower colors: Violet Blue White

Bloom season: Spring

Winter landscape value: Moderate, semi-evergreen




Noteworthy cultivars: Bronze Beauty, metallic leaves;

Burgundy Glow, tricolor variegated; Cristata,

crinkled leaves; Silver Beauty, white variegated

leaves

Common name: hybrid anemone

Scientific name: Anemone xhybrida

Type: Flower


Flower colors: Pink White

Bloom season: Fall

Light req.: Partial shade



Noteworthy cultivars: Bressingham Glow, dark pink;

Honorine Jobert, white; Max Vogel, pink

Common name: long-spurred columbine

Scientific name: Aquilegia hybrids

Type: Flower


Flower colors: Violet Lavender Blue Yellow Red

Pink White





Noteworthy cultivars: Biedermeier Strain, 12" small

flowers white, pink, purple; McKana hybrids, 30"

mixed colors

4-16

Common name: New England aster

Scientific name: Aster novae-angliae

Type: Flower

Plant height (feet): 2.0 - 6.0

Flower colors:Violet Lavender Blue Red Pink

White

Bloom season: Fall




Noteworthy cultivars: Alma Potschke, 3-4' pink;

Purple Dome, 18" purple; September Ruby, 3-5'

ruby red

Common name: false spirea or Arend’s hybrid

astilbe

Scientific name: Astilbe xarendsii

Type: Flower


Flower colors: Lavender Red Pink Maroon

White

Bloom season: Summer


Soil moisture req.: Moderate to Wet


Noteworthy cultivars: Erica, 36" pink; Fanal,

24" deep red; Irrlicht, 24" white

Common name: snow-in-summer

Scientific name: Cerastium tomentosum

Type: Groundcover


Flower colors: White


Winter landscape value: Moderate, evergreen




Noteworthy cultivars: Silver Carpet, compact

Common name: leadwort

Scientific name: Ceratostigma plumbaginoides

Type: Groundcover


Flower colors: Blue

Bloom season: Summer to Fall





Common name: clematis

Scientific name: Clematis hybrids

Type: Vine



Orange Red Pink Maroon White

Bloom season: Spring to Summer



USDA Hardiness Zone: 4/5

Noteworthy species & cultivars: C. jackmanii, dark

blue-purple; Henryi, white; many more

Common name: lance-leaf coreopsis

Scientific name: Coreopsis lanceolata

Type: Flower


Flower colors: Yellow, some with Maroon or

Brown markings





Noteworthy cultivars: Baby Sun, 12"; Early

Sunrise & Sunray, 18" double flowers

Common name: threadleaf coreopsis

Scientific name: Coreopsis verticilata

Type: Flower


Flower colors: Yellow Pink



Soil moisture req.: Moderate Tolerates Dryness


Noteworthy cultivars: Moonbeam, 10-15" soft

creamy yellow; Zagreb, 18" bright yellow

Common name: perennial pinks

Scientific name: Dianthus species

Type: Flower


Flower colors: Pink Red White

Bloom season: Spring to Summer

Winter landscape value: Moderate, some semi-

evergreen




Noteworthy species: D. deltoides,maiden pinks; D.

gratianopolitanus, Cheddar pinks; D. plumarius,

grass pinks;, D. x allwoodii, Allwood pinks

4-17

Common name: purple coneflower

Scientific name: Echinacea purpurea

Type: Flower


Flower colors:

Pink White with Brown to Black center disks





Noteworthy cultivars: Bright Star, 2-3' bright

rose-red; Magnus, flat rays rosy-purple; White

Swan, 2-3' white

Common name: barrenwort or bishop’s-hat

Scientific name: Epimedium species

Type: Groundcover


Flower colors: Lavender Yellow Red White





Noteworthy species: E. pinnatum, Persian

epimedium; E. x rubrum, red barrenwort;

E. x versicolor and its cv. Sulphureum, bicolor

barrenwort

Common name: perennial blanket flower

Scientific name: Gaillardia xgrandiflora

Type: Flower


Flower colors: Yellow Red





Noteworthy cultivars: Baby Cole, dwarf red &

yellow; Goblin, dwarf red & yellow; Sun God,

24-30" yellow & brown; Yellow Queen, 24-30"

yellow

Common name: cranesbill or true geranium

Scientific name: Geranium species

Type: Flower


Flower colors: Violet Lavender Blue Pink

Maroon White

Bloom season: Spring into Summer




Noteworthy species/cultivars:

G. endressii cv. Wargrave Pink, Pyrean cranesbill,

G. himalayense cv. Johnson’s Blue, lilac

cranesbill, G. macrorrhizum cv. Album, cv.

Bevan’s Variety & cv. Ingwersen’s Variety, bigroot

geranium

Common name: daylily

Scientific name: Hemerocallis hybrids

Type: Flower

Plant height (feet): 1.0-3.0+

Flower colors: Violet Lavender Yellow Orange

Red Pink Maroon White

Bloom season: Summer and re-blooms into Fall




Noteworthy cultivars: many

Common name: coral bells

Scientific name: Heuchera species and hybrids

Type: Flower







Noteworthy cultivars: many selections & hybrids

from H. americana, H. micrantha and H.

sanguinea and even interspecific hybrids

involving Tiarella cordifolia know as

xHeucherella

Common name: hosta or plantain-lily

Scientific name: Hosta hybrids

Type: Flower


Flower colors:

Violet Lavender White






4-18

Common name: bearded iris

Scientific name: Iris hybrids

Type: Flower


Flower colors:Violet Lavender

Blue Yellow Orange Red Pink

Maroon Tan nearly Black White






Common name: spotted dead-nettle

Scientific name: Lamium maculatum

Type: Groundcover


Flower colors: Violet Red Pink White


Winter landscape value: Moderate, semi-

evergreen




Noteworthy cultivars: Album, white flowers;

Beacon Silver, pink flowers with silvery leaves;

Shell Pink, pink flowers; White Nancy, white

flowers with silvery leaves

Common name: Shasta daisy

Scientific name: Leucanthemum x superbum

Type: Flower


Flower colors: White with yellow centers





Noteworthy cultivars: Alaska, 2-3'; Diener’s

Double, 24" with double flowers; Little Miss

Muffet, 12"; Snowcap, 15"

Common name: garden lily

Scientific name: Lilium hybrids

Type: Flower


Flower colors: Yellow Orange Red Pink

Maroon White





Noteworthy cultivars: many in several size and

form categories

Common name: creeping lily-turf

Scientific name: Liriope spicata

Type: Groundcover


Flower colors: Lavender White



evergreen





Common name: bee-balm or bergamot

Scientific name: Monarda didyma

Type: Flower


Flower colors: Violet Lavender Red Pink

Maroon White





Noteworthy cultivars: Cambridge Scarlet, 3'

bright scarlet; Croftway Pink, 3-4' pink; Snow

White, 3' white; Violet Queen, 3' purple

Common name: garden peony

Scientific name: Paeonia hybrids

Type: Flower







Noteworthy cultivars: many in several flower

forms

Common name: oriental poppy

Scientific name: Papaver orientale

Type: Flower


Flower colors: Orange Red Pink White all

with Black interior marks





4-19

Noteworthy cultivars: Allegro, bright orange-

scarlet; China Boy, orange & white; Warlord,

red; Watermelon, pink

Common name: Russian sage

Scientific name: Perovskia atriplicifolia

Type: Flower


Flower colors: Blue





Noteworthy cultivars: Blue Haze, pale blue;

Blue Spire, violet flowers with deeply dissected

leaves; Longin, erect habit

Common name: garden phlox

Scientific name: Phlox paniculata

Type: Flower


Flower colors: Violet Lavender Red Pink

White


Light req.: Full sun Partial Shade




Common name: creeping phlox

Scientific name: Phlox subulata

Type: Groundcover


Flower colors: Violet Lavender Blue Red

Pink White



evergreen





Common name: Christmas fern

Scientific name: Polystichum acrostichoides

Type: Fern


Flower colors: N.A.

Bloom season: N.A.

Light req.: Partial shade Full Shade Deep Shade




Common name: orange coneflower

Scientific name: Rudbeckia fulgida

Type: Flower


Flower colors: Yellow Orange w/Black centers





Noteworthy cultivars: Goldsturm, 24"

Common name: hybrid perennial salvia

Scientific name: Salvia hybrids

Type: Flower


Flower colors: Violet Blue

Bloom season: Spring and Summer




Noteworthy cultivars: May Night, 18" indigo;

East Friesland, 18" dark violet

Common name: showy stonecrop or showy

sedum

Scientific name: Sedum spectabile

Type: Flower



Bloom season: Fall

Winter landscape value: Moderate, dead plants

stand through winter




Noteworthy cultivars: Brilliant, 18" bright pink;

Carmen, 18" rose-pink; Iceberg, 18" white;

September Glow 20" rich pink; Autumn Joy 24"

pink, then copper-red (this is of hybrid origin,

not a true

S. spectabile)

Common name: barren strawberry

Scientific name: Waldsteinia species

Type: Groundcover


Flower colors: Yellow


4-20


evergreen




Noteworthy species: W. fragariodes, (North

American native); W. ternata, (Euro-Asiatic

native)

Hardy Bulbs


Information




chapter.

Common name: crocus

Scientific name: Crocus hybrids


Flower colors:

Violet Lavender Blue Yellow White

Bloom season: Early Spring


Soil moisture req.: Moderate but well-drained


Noteworthy cultivars: Early Perfection, violet-

blue; Peter Pan, white with orange pistil

Common name: common snowdrop

Scientific name: Galanthus nivalis


Flower colors: White with Green markings

Bloom season: Early Spring




Noteworthy cultivars: Flore Pleno, double

flowers

Common name: garden hyacinth

Scientific name: Hyacinthus orientalis



Orange Red Pink White

Bloom season: Mid Spring to Late Spring




Noteworthy cultivars: very many\

Common name: daffodil or narcissus

Scientific name: Narcissus hybrids


Flower colors:

Yellow Orange Pink White

Bloom season: Early Spring to Late Spring




Noteworthy cultivars: very many species, classes

and cultivars

Common name: tulip

Scientific name: Tulipa hybrids



Orange Red Pink Maroon White

Bloom season: Early Spring to Late Spring




Noteworthy cultivars: very many species, classes

and cultivars

Ornamental Grass


Information




chapter.

Common name: giant reed

Scientific name: Arundo donax

Plant height: to 12+

Winter landscape value: Low, naked stalks may

stand




Noteworthy cultivars: Macrophylla, large leaves;

Variegata, white striped leaves

Common name: feather reed grass

Scientific name: Calamagrostis x acutiflora

Plant height: Leaves, 1.5; Flowers, to 4.0

4-21

Winter landscape value: High, bunches stand

through winter




Noteworthy cultivars: Karl Foerster (Stricta),

tight & upright clump; Overdam, similar but

variegated

Common name: sedge

Scientific name: Carex species

Plant height: 1.0-4.0

Winter landscape value: Low, variable

Light req.: Full sun Partial Shade

Soil moisture req.: Moderate to Wet

USDA Hardiness Zone: 5/6 +

Noteworthy species: C. grayi; C. morrowii;

Common name: blue fescue

Scientific name: Festuca glauca


Winter landscape value: Moderate


Soil moisture req.: Moderate Tolerates Dry


Noteworthy cultivars: Elijah Blue, blue & long-

lived; Tom Thumb, dwarf

Common name: Chinese silver grass

Scientific name: Miscanthus sinensis

Plant height: Leaves, 3.0-6.0; Flowers 4.0-8.0

Winter landscape value: High, flowers and

foliage retained all winter


Soil moisture req.: Moderate, some Tolerates

Wetness


Noteworthy cultivars: Adagio, dwarf;

Gracillimus, fine-textured foliage; Morning

Light, fine-textured foliage & upright; Strictus,

cross-striped leaves & upright; + many more

Common name: switchgrass

Scientific name: Panicum virgatum


Winter landscape value: High




Noteworthy cultivars: Heavy Metal, blue;

Rotstrahlbusch, reddish in fall

Common name: perennial fountain grass

Scientific name: Pennisetum alopecuroides

Plant height: Leaves, 1.0+; Flowers, to 3.0

Winter landscape value: High




Noteworthy cultivars:

Hameln, dwarf; Little Bunny, very small;

Moudry, dark purple flowers

Common name: plume grass

Scientific name: Saccharum ravennae

Plant height: Leaves, 3.0; Flowers, to 12+

Winter landscape value: Low, mostly lodged




4-22

Review & Study Questions

1. What is the key characteristic thatdifferentiates a herbaceous plant from awoody plant such as a shrub or tree?

2. What are the categories of plant lifecycles?

3. Each group of herbaceous ornamentalshas particular qualities that determinetheir use in the landscape (landscapefunction). Review each group and theirprimary landscape functions.

4. List three annuals that are adapted to fullshade conditions.

5. What soil preparation is needed to growannual flowers successfully? Whatshould be done differently or in additionwhen preparing soil for perennials?

6. What factors impact the plant spacingdecision when planting annuals?

7. What fertilization is recommended forseason-long management of annuals?How does fertilizer applied in the bedpreparation phase impact this activity?

8. What are the options available for weedcontrol in annuals? In perennials? Inornamental grasses?

9. What are the key site factors thatdetermine what perennials are suited for aparticular landscape?

10. List three perennials that are fallblooming.

11. What are the handling and plantingmethods for bare root perennial plants?

12. Discuss the needs and methods of plantsupport for culture of perennials.

13. What is the purpose of division ofperennials. When should most perennialsbe divided? Cite some exceptions to thegeneral rule.

14. What is the utility of winter mulch in theculture of perennials?

15. What is the key aspect of well preparedsoil for the growing of hardy bulbs?

16. Discuss foliage management of hardybulbs. How long should leaves remainafter blooming? What does all foliageand no flowers indicate?

17. What is the growth habit of the bestornamental grasses for use in the Indianalandscape?

18. What are the annual managementrequirements of ornamental grasses?How does this compare to typicalperennials?

For Additional Reading

Armitage, A. 1998. Herbaceous PerennialPlants, Second Edition. Stipes Pub. Co.,Chamapign, IL.

Armitage, A., A. Kays, & C. Johnson. 2001.Armitage’s Manual of Annuals,Biennials, and Half-Hardy Perennials.Timber Press, Portland.

Brickell, C. & J. Zuk. 1997. The AmericanHorticultural Society A - Z Encyclopediaof Garden Plants. D-K Publishing, NewYork.

Bush-Brown, L. & J., rev. ed. H. S. Irwin &Brooklyn Bot. Gdn. 1996. America’sGarden Book. Macmillan, New York.

4-23

Darke, R. 1999. Color Encyclopedia ofOrnamental Grasses. Timber Press,Portland.

Ellis, B. 2000. Taylor’s Guide to Annuals.Houghton Mifflin Co., New York.

Ellis, B. 2001. Taylor’s Guide to Bulbs.Houghton Mifflin Co., New York.

Ellis, B. 2001. Taylor’s Guide to Perennials.Houghton Mifflin Co., New York.

Holmes, R. 1996. Taylor’s Guide toOrnamental Grasses. Houghton MifflinCo., New York.

MacKenzie, D. 1997. Perennial GroundCovers. Timber Press, Portland.

Websites of Interest

Purdue Landscape and Nursery Thesaurus.Follow links to herbaceous perennialsunder Plant Material. http://bluestem.hort.purdue.edu/plant/

Ohio State University Plant Facts site: http://hcs.osu.edu

Perennial Plant Association List of MemberBusinesses

http://www.perennialplant.org

All-America Rose Selectionshttp://www.rose.org/

Some Commercial Sites

Ball Seed Companyhttp://www.ballseed.com/

Klehm’s Song Sparrow Nurseryhttp://www.klehm.com/

David Austin Roses in Great Britainhttp://www.davidaustinroses.net/american/

main.asp

Sunshine Farm and Gardenshttp://www.sunfarm.com/plantlist/

plantlist.phtml

Terra Nova Tissue Culture Nurseryhttp://www.terranovanurseries.com/

Plant Delights Nurseryhttp://www.plantdelights.com/Catalog/

Current/page1.html

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