Specifying and Sourcing Native Plant Materials

Introduction to Landscapes on the Edge: Design & Implementation of Projects on Puget Sound Shorelines and Urban Ravines

Center for Urban Horticulture

November 16, 2016

Scott Moore

Snohomish County Public Works

Native Plant Program

Project Sequence

Specifying and Sourcing Native Plant Materials

• Regional flora

• Project concept

• Secured funding

• Sites assessment

• Restoration plan: goals, objectives, timeline, etc

• Planting Plan: site conditions, soils, elevations, etc.• Plant palette, numbers, sizes, arrangement

•Specify & Source plant materials• Site prep

• Planting

• Establishment

• Monitoring

Specifying and Sourcing Native Plant Materials

Target Plant Concept

Specifying and Sourcing Native Plant Materials

Target Plant Concept

Implementation

3 (or 4) Target Plant concepts

• What type of plant material should be used (seed, cuttings, or plants)?

• What are appropriate genetic sources for each species? Provenance

• What is the proper season for outplanting or seeding (the outplanting or seeding window)

• What methods will be used to install plant materials & what post installation plant care is appropriate?

• Right place, right plant

Provenance

• highest regional genetic affinity• Genetic considerations are fundamental to the success of ecological

restoration• local versus non-local plant material• based on sound population genetic, ecological, and evolutionary theory

research; • selection of plant material to be used in ecological restoration is often

driven by the specific project goals, availability and quality of plant material, site conditions, and scale of the project.

• issues related to small population dynamics, gene flow in the modern landscape, and gene expression affecting community structure and ecosystem functions can affect the success of ecological restoration activities.

• genetics of small populations (inbreeding and outbreeding depression, founder effects, and fitness consequences of reduced genetic variation

Seed zones

• Elevation• Temperature• Precipitation

• Watershed

Plant Establishment Methods

• Natural Recruitment – maximizing natural regeneration• Proximity of natural & desirable plant community

• Optimize recruitment

• Direct Seeding

• Outplanting Nursery stock

Planting Season

•Oct to April in PNW • Coincides with root growth

period• Fall optimal for woody

plants • Bare root late winter- early

spring• Perennials early spring?• Broader time for container

stock• Summer?

• Soil moisture or watering?

Optimal planting times for site & material

Type of plant material

•Seed

•Live stakes

•Plugs

•Bare root

•Container or barerootedcontainer stock

•Salvaged

•Ball and Burlap

Plant materials selection matrix

Acquisition

Availability: commonly occuring? Relatively rare?

Plan early: increased demand,

Sources

Work horse species

Specialist species

Standard specifications

• Common in engineering plan sets

• Common in landscaping plans

• Container vs plant size, caliper, branching, etc.

Plan development and Review

• You maybe creating your own plan in house & doing all the on the ground work. But your grant source may want to know what your plan is!

• Or you are reviewing plan from second party (consultant)

• And maybe contracting with a third party to actually do the construction work

• And maybe a subcontractor is securing plants and doing installation

• And a plan and specifications will help in estimating costs.

Specification minimums

• Plant name• Common• Scientific (Genus species)

• Quantity

• Size (container or material type)

• Spacing• Per acre (trees per acre, tpa) (shrubs per acre, spa) 435 tpa = 10’ OC• On center (3 ft on center)

• Plant type (evergreen or deciduous)

• Other• Soil moisture• Light regimen• WL indicator rating (OBL, FACW, FAC, Upland)

Beach backshore Zone 1 ~15,000 sq ft. 3750

spacing stock type quantity

American dune grass Leymus mollis 2' oc plug 2000

silver bursage Ambrosia chamissionis 2' oc plug 1000

gumweed Grindelia integrifolia 2' oc plug 500

beach pea Lathyrus japonicus 4' oc plug 500

big headed sedge Carex macrocephela plug 200

seaside sandplant Honckenya peploides

Ground cover Zone 2 3000 sq ft

salal Gaultheria shallon 3' oc 1 gal 300

beach silvertop Glehnia leiocarpa 2' oc plug 200

silverbursage Ambrosia chamissionis 2' oc plug 100

upland Zone 3 2400 sq ft

nootka rose Rosa nutkana 2g 80

snowberry Symphoricarpos alba 2g 80

Hooker willow Salix hookeriana 2g 80

oceanspray Holodiscus discolor 2g 25

cow parsnip Heracleum lanatum 2g 20

riparian 1800 sq ft

tall oregon grape Mahonia aquifolium 3' oc 3g 100

twinberry honeysuckle Lonicera involucrata 3' oc 2g 100

oceanspray Holodiscus discolor 3' oc 2g 25

cow parsnip Heracleum lanatum 10' oc 2g 40

beach wormwood Artemesia suksdorfia 5' oc 1g 300

understory** 2400 sq ft

Sitka spruce Picea sitchensis 10' 2g 10

shore pine Pinus contorta 10' 2g 10

redcedar Thuja plicata 10' 2g 10

bald hip rose Rosa gymnocarpa 3' 2g 60

snowberry Symphoricarpus alba 3' 2g 60

salal Gaultheria shallon 3' 2g 60

twinberry Lonicera involucrata 3' 2g 60

trailing blackberry Rubus ursinus 3' 1g 100

swordfern Polystichum munitum 5' 2g 100

strawberry Frageria virginiana 2' 2g

kinnickkinnick Arctostaphylos uvisursi

** in event that Evt Parks decides to remove poplars….

switch ROGY to RONU, increase conifer component, add PSME.

Howarth Park Nearshore Plantingimportant key species

included in base planting plan

Seed

• Low Cost?•Easy handling•Native seed more widely

available• Contract collection• Commercial seed

production

•Non-native placeholder?• Low maintenance•High genetic diversity

Seed Considerations

• Grass, herbs, shrubs

• Acquisition/availability

• Origin

• Hand collected or field production

• contract grown

• Direct seed or nursery production

• Expense

• Application methods

• Keep mixes simple using common species

Cuttings: piece of stem, branch, or root, separated a host plant and used to create a new plant:.

Live stakes: .5 – 1.5 inch dia 2-4 ft longWhips: soil bioengineering: fascines, brush mats, etc.

.25-1.5 inch dia 4- 6ft longPoles: 1.5 – 3 inch dia 4 - 8ft longPosts: 3 – 12+ inch dia 8 ft – 16 ft long….

VersatileInexpensive to produceEasy InstallationEasy handlingHigh mortalityLimited Species Limited to dormant season*Low maintenanceLow genetic diversity “clones”

Rooting potential

Survival potential

Target plant density

Area to plant

Desired established plant densities

Length of cuttings.

Live Stakesrelatively short length cutting inserted

vertically into ground.

Vegetative applications and installations

Ravines, Steep slopes, and Bluffs

soil plant bioengineering strategies

Plants appropriate for live staking

• Willow• Sitka Salix sitchensis

• Pacific Salix lucida

• Hooker Salix hookeriana

• Scouler Salix scouleriana

• Dogwood• Red osier Cornus sericea

• Rose family• Ninebark Physocarpus capitatus

• Salmonberry Rubus spectabilis

• Honeysuckle• Twinberry Lonicera involucrata

• Snowberry Symphoricarpos albus

Rooted cuttings

• Increased resiliency

• Summer bioengineering installations

• Browse protection

• Provide better leaf area to root area ratio

• Low soil volume container plant

• Pre-rooted live stake

Bareroot

Great care in handling

Greater skill for planting

Low cost

Medium mortality

Medium aftercare

Seasonal availability

Don’t let those roots dry out!

Bareroot sizing, provenance, availability

wacd-pmc

Plugs

usually herbaceous plants and graminoids

Low cost per plant

Low handling cost

Lower mortality

Limited species

Medium planting skill

Low - Medium mortality

ContainerHigher cost per plantLow handling cost Lower mortalityMost species availableLower skill for planting*Medium mortalityMedium aftercare

Variety of Container types and volumes

4” 1 gal2, 3, 5, 7, 10+

Tall potsPrerooted livestakes

Variety of containers

• Containers (variety of volumes)

• 4”

• 1gal

• 2, 3, 5, +

• Tall pots

• Prerooted livestakes

Salvaged material

• Transplanting difficulty is species specific

• Site permission

• Positive plant identification,

• Some difficulty in prep/digging, and handling/transporting..

• Storage/Nurturing

• Don’t lose your Ethics

Balled and Burlap (B&B)

•High cost per plant

• Lower mortality?

• Limited species

•Greater skill for planting

•High aftercare needs

•Check for severe root pruning

Estimating your plant needs

• Desired space/acreage to plant

• Available funds

• Plant spacing per stock type

• Many online plant calculators

Spacing

Function- (landscaping, change light/water regimes, mortality rates, erosion control)

Habitat – desert, wetlands, forests

Existing site conditions (invasive species, existing trees or native shrubs)

Spacing

In general-

Trees 8 – 20’ OC (100-700 TPA)

Shrubs 2 - 4’ OC

Groundcovers 1-2’

Live Stakes 1-3’ OC

Spacing and cost calculators available on line

Sources of Native Plants

Regional PNW Native Plant Nurseries

Just Google it! Or WNPS.org, local county

from inventory

contract grow

Conservation District Plant Sales

Salvage or on site harvest

Contract Seed collectors

Contingency

• Site conditions change or are not as indicated in plan set

• Mortality

• Alternative Sources

• Substitutions

• Unicorns

Go Plant!