Is It Time To...?

Kansas State University

Ward Upham

Preventing Common Horticulture Plant Problems

Kansas State University

Ward Upham

Is It Time To:Control Henbit and Other Winter Annuals

Henbit

Is It Time To:Spray for Henbit and Other Winter Annuals

Chickweed

Winter Annual Control

▪Use 2,4-D ,Trimec, Weed-B-Gon, Weed Free Zone

▪Best to spray in fall

Henbit Chickweed

Winter Annual Control

▪Best to spray in fall

▪If spray early in spring, use combination product such as Trimec, Weed-B-Gon, Speed Zone, or Weed Free Zone

▪Spraying as late as mid-April or later is usually a waste of time and money

Is It Time To:Fertilize Cool-Season Grasses

Cool-Season Grasses

▪Tall Fescue & Kentucky Bluegrass

Tall Fescue Kentucky Bluegrass

When to Fertilize Cool-Season Grasses

▪September▸Most important fertilization of year▸Use 1 pound nitrogen (N) per 1000 square feet▸Quick-release OK

▪November▸Second most important fertilization ▸Use 1 pound N per 1000 square feet▸Quick-release OK

▪May▸Optional; use if irrigate, apply 1 pound of N per 1000 square

feet▸Use fertilizer with at least 1/4 N as slow-release

Is It Time To:

Fertilize Warm-Season Grasses

Warm-Season Grasses

▪Bermudagrass, Zoysiagrass and Buffalograss

BermudagrassZoysiagrassBuffalograss

When to Fertilize Warm-Season Grasses▪1 pound nitrogen per 1000 square feet per year▸May be all that buffalo and zoysia need; too much on

zoysia and thatch builds up

▸Some people never fertilize buffalo or zoysia

▸Apply once in June

▪2 pounds nitrogen per 1000 square per year▸Apply May and July with 1 pound each app

▸Maximum amount for buffalo and zoysia but minimum amount for bermuda

▪3 pounds nitrogen per 1000 square feet per year▸Apply May, June and early August

Is It Time To:Seed Cool-Season Lawns

Better to Seed in the Fall Rather than Spring

▪Warmer soils and turf comes up faster

▪Less competition from weeds

▪More time to become established before the heat stress of summer

If You Weren’t Able to Seed in the Fall▪Consider Dormant Seeding if have areas to

thicken up▸Seed from December through mid-March▸Must have good seed-soil contact

–Rake in with hand rake–Use slit-seeder–Verticut and then seed–Core aerate and seed

▪Seed as early in spring as possible▸ Leave ground bare if you can do so without erosion ▸Can use Tupersan to control crabgrass▸May have to redo in fall

Is It Time To:

▪Look for darker “hot spots”. Often have purplish tinge.

▪Best to allow turf to undergo some stress early in season.

▪Attempt to apply 3/4 to 1 inch of water each time you irrigate.

Water the Lawn

Is It Time To:

▪Blades should be sharpened about every 10 hours

▪Sharp blades cut cleaner, quicker and require less energy

Sharpen Mower Blades

Is It Time To:

▪Leaves swollen, distorted and have reddish hue.

Treat for Peach Leaf Curl

Peach Leaf Curl

▪Single fungicide application will control.▪Must apply in fall after leaf drop or early spring

before bud swell.▪Use chlorothalonil (Daconil), liquid lime sulfur or

Bordeaux mixture.

Is It Time To:

Treat for Cedar-Apple Rust

Cedar-Apple RustHost Plants

▪Junipers

▪Apples or crabapples

Cedar-Apple RustBackground

▪Must have both plants present for disease to occur. However, juniper removal is usually not practical as all junipers within ½ to 2 miles of apples would have to be eliminated.

▪Juniper - though disease unsightly on juniper, will generally not cause serious damage.

▪Apple - can cause premature defoliation and thereby weaken tree.

Cedar-Apple RustSymptoms on Apple

▪In late spring or early summer, yellow-orange spots appear on the leaves.

Cedar-Apple RustSymptoms on Apple

▪Eventually, tube-like projections form on bottom surface of the leaf.

Cedar-Apple RustSymptoms on Apple

▪In late spring or early summer, yellow-orange spots appear on the leaves.

▪Eventually, tube-like projections form on bottom surface of the leaf.

▪Leaves with numerous spots drop during the summer. This stresses the tree and reduces fruit set and yield the following year.

Cedar-Apple RustSymptoms on Apple

▪In late spring or early summer, yellow-orange spots appear on the leaves.

▪Eventually, tube-like projections form on bottom surface of the leaf.

▪Leaves with numerous spots drop during the summer. This stresses the tree and reduces fruit set and yield the following year.

▪New leaves are formed if defoliation is severe enough.

Cedar-Apple RustSymptoms on Juniper

▪Produces reddish-brown galls on twigs of junipers that are ½ to 2 inches in diameter.

Cedar-Apple RustSymptoms on Juniper

▪In April, galls swell and produce orange, one- inch long tendrils in a gelatinous mass during wet weather.

Cedar-Apple RustSymptoms on Juniper

▪It takes two years for galls to develop. Galls only produce spores the second year.

Cedar-Apple RustRecommendations for Crabapple

▪Best control on crabapples is to plant resistant varieties.

▪Varieties resistant to both scab and rust include:▸Donald Wyman▸Bob White▸Golden Raindrops▸Prairiefire▸Red Jewel

Cedar-Apple RustSpray Recommendations for Apples & Crabs

▪First spray should be applied when orange tendrils on junipers appear. (Early April)

▪Repeat applications as long as juniper galls remain active. (late May)

▪Triadimefon (Bayleton, Green Light Fung-Away) or myclobutanil (Immunox)

▪Immunox labeled for both apples and crabapples and for both rust and scab

Cedar-Apple RustSpray Recommendations for Junipers

▪Rarely sprayed because disease normally does not cause serious damage to junipers.

▪If spray, apply three to four fungicide applications sprayed at 10-day intervals, beginning in early July.

▪Can use Bordeaux mixture, ferbam, and Bayleton.

▪Because galls take two years to develop, will not notice benefit until the second year.

Is It Time To:

Treat for Sphaeropsis Tip Blight

Sphaeropsis Tip Blight

▪Austrian, Ponderosa, Scotch, and Mugo

▪Most severe on mature (30 years or older) Austrian pines.

Sphaeropsis Tip BlightSymptoms

▪In late May or early June, new developing shoots fail to elongate properly and turn yellow or tan.

▪Small droplets of resin often form on the stunted needles.

▪Needles tend to remain attached to the tree.

▪Repeated infections can cause death of entire branches.

Sphaeropsis Tip BlightControl Recommendations

▪Two to three applications of fungicide needed.

▪Apply first about the third week in April just as new buds are elongating.

▪Following sprays spaced at 10 - 14 day intervals.

▪Removal of dead shoots may help but will not give complete control since disease carried on cones.

▪Use coppers (Bordeaux, Tenn-Cop) or thiophanate (Fungo, Cleary’s 3336).

Is It Time To:

Treat for Sycamore Anthracnose

Sycamore Anthracnose

▪Young leaves may wither and turn black.▪Older leaves may have brown areas that follow

the major veins of the leaf.

Anthracnose on SycamoreRecommendations

▪Usually chemical controls unnecessary as tree will releaf.

▪If want to control disease, use thiophanate-methyl (Cleary’s, Fungo), mancozeb, fixed coppers, or Bordeaux mixture.

▪Sometimes, professional arborists use a September injection of a fungicide such as Arbotect to protect sycamore trees that have a history of anthracnose. Inject 2 consecutive years.

Is It Time To:

Treat for Bagworms

Bagworms

▪Junipers and arbovitae are favorites

▪Can also attack other ornamental shrubs, shade, and forest trees.

BagwormsLife Cycle

▪Bags look like Christmas ornaments.

BagwormsLife Cycle

▪Bags look like Christmas ornaments.

▪Young bagworms hatch in May in Kansas.

Larva

May 22

BagwormsLife Cycle

▪Bags look like Christmas ornaments.

▪Young bagworms hatch in May in Kansas.

▪Bagworms spin silken bags around themselves.

July 7

BagwormsLife Cycle

▪Female is wingless and never leaves the bag. Male is a small, gray, clear-winged moth that resembles a wasp.

Female Bagworm Male Bagworm

BagwormsDamage

▪Feed on foliage of host plant.

▪Often damage is not noticed until bagworm so large that it is hard to control.

BagwormsControl Recommendations

▪Small infestations can be picked off by hand.

▪Wait at least a week after seeing first larvae appear before spraying to allow complete emergence of insects.

▪Can use acephate (Systemic Insect Control), malathion, or permethrin (numerous trade names) for control.

Is It Time to:Do Something About Pine Wilt

▪Most severe on Scotch pine

▪Also reported on Austrian and white pines

Pine WiltSymptoms

▪Trees wilt and die rapidly

▪Needles turn brown and remain attached to tree

▪Trees have reduced resin production. Twigs are brittle and dry and site of branch removal does not produce resin

▪Symptoms usually appear from August through December

Pine WiltControl Recommendations

▪First, confirm disease if it is rare in your area by sending branch sample at least 2 inches in diameter to K-State Diagnostic Lab ($10 fee)

▪Cannot save infected trees

▪Help prevent spread to nearby trees by removing infected trees to ground level.