Horticulture 2019 Newsletter: No. 23 June 11, 2019

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http://hnr.k-state.edu/extension/info-center/newsletters/index.html

 

Blog Post: http://www.ksuhortnewsletter.org Video of the Week: Controlling Bagworms

http://kansashealthyyards.org/component/allvideoshare/video/bagworms-controlling?Itemid=101

 

 

UPCOMING EVENTS

Turf & Ornamentals Field Day

Thursday, August 1

K-State Research & Extension Center, Olathe

 

The K-State Turf and Ornamentals Field Day will be held Thursday, August

1 at the Research & Extension Center in Olathe (35230 W. 135th).   The

field day program is designed for all segments of the turf industry –

lawn care, athletic fields, golf courses, and grounds maintenance.

Included on the program are research presentations, problem diagnosis,

commercial exhibitors, and equipment displays. There will be time to see

current research, talk to the experts and get answers to your questions.

 

1 hour of pesticide recertification credit is available in both 3A and

3B, as well as GCSAA education points.  For more information and to

register, go to: https://2019turfday.eventbrite.com

 

VEGETABLES

Do Not Over-Fertilize Tomatoes

Though tomatoes need to be fertilized to yield well, too much

nitrogen can result in large plants with little to no fruit. Tomatoes

should be fertilized before planting and sidedressed with a nitrogen

fertilizer three times during the season.

The first sidedressing should go down one to two weeks before the

first tomato ripens. The second should be applied two weeks after the

first tomato ripens and the third one month after the second. Common

sources of nitrogen-only fertilizers include nitrate of soda, urea, and

ammonium sulfate. Blood meal is an organic fertilizer that contains

primarily, but not

exclusively, nitrogen. Use only one of the listed fertilizers and apply

at the rate given below.

Nitrate of soda (16-0-0): Apply 2/3 pound (1.5 cups) fertilizer per

30 feet of row.

Blood Meal (12-1.5-.6): Apply 14 ounces (1.75 cups) fertilizer per

30 feet of row.

Urea (46-0-0): Apply 4 ounces (½ cup) fertilizer per 30 feet of row.

Ammonium Sulfate (21-0-0): Apply 0.5 pounds (1 cup) fertilizer per

30 feet of row.

If you cannot find the above materials, you can use a lawn

fertilizer that is about 30 percent nitrogen (nitrogen is the first

number in the set of three) and apply it at the rate of 1/3 pound (3/4

cup) per 30 feet of row. Do not use a fertilizer that contains a weed

killer or weed preventer. (Ward Upham)

 

New Potatoes

Many gardeners look forward to harvesting new potatoes at this time

of year. New potatoes are immature and should be about the size of

walnuts. Pull soil away from the base of the plants to see if the tubers

are the desired size. If they are, dig entire plants and allow the skins

of the exposed tubers to dry for several hours before gathering. These

young potatoes are very tender and prone to the skin “slipping” unless

they are given a few hours to dry. Even then these immature potatoes

will not store well. Red-skinned varieties are often preferred as they

are the earliest to produce. (Ward Upham)

 

FRUIT

Fruit Reminders

Fruit gardens have certain chores that need to be done through the

growing season such as the following.

* Remove some fruit from heavily loaded apples and peaches (if the

flower buds weren’t

killed by frost) to improve fruit size and prevent limbs from breaking.

Apples and peaches should be spaced about every 6 to 8 inches. Note that

is an average spacing.  Two fruit can be closer together if the average

is correct.

* Remove sucker growth from the base of fruit trees and grape vines.

* Remove water sprout growth from fruit trees. Water sprouts grow

straight up from existing branches.

* Water as needed.  About 1 inch of water per week is about right

though more may be needed during hot spells.

* “Comb” new growth on grape vines so these new shoots hang down

for greater

exposure to sunlight.

* Continue disease and insect control to prevent fruit damage. For

more detail on fruit sprays, see “Spray Schedules” on our publication

page. (Ward Upham)

 

PESTS

Grasshoppers

Grasshopper nymphs, both longhorned (typically not a pest), and

shorthorned are common and they will probably just keep increasing in

density for another month or more. Another reminder that the best time

to manage them is while they are still small and thus, less mobile. An

application of an insecticide labeled for grasshopper control is most

effective, cheaper, and less environmentally disruptive if applied in a

timely manner relative to grasshopper development. (Jeff Whitworth and

Holly Davis)

 

Editor’s Note: More detailed information on grasshopper control is

available our “Common Plant Problem” publication “Grasshoppers.”

 

Look for Bagworms Now

Most calls on how to control bagworms come in during late-July to

early-August when damage appears. Bagworms are difficult to control when

they are that large. They are much easier to kill while small.

Bagworms overwinter as eggs inside the dead female’s bag. Young

larvae normally hatch and emerge during mid- to late-May in Kansas. Now

would be a good time to use control measures. However, make sure the

bagworms are present by looking for a miniature version of  the mature

bagworm.  Also, check to be sure the bagworms are alive before spraying.

Predators and parasites can sometimes naturally control this pest.

 

Insecticides commonly used for controlling bagworms include:

acephate (Orthene)

permethrin (38 Plus Turf, Termite & Ornamental Insect Spray; Eight

Vegetable, Fruit & Flower  Concentrate; Lawn, Garden, Pet, & Livestock

Insect Spray)

cyfluthrin (BioAdvanced Vegetable and Garden Insect spray)

bifenthrin (Bug Blaster II, Bug-B-Gon Max Lawn and Garden Insect

Killer)

lambda-cyhalothrin (Spectracide Triazicide, Bonide Caterpillar

Killer)     spinosad (Conserve; Natural Guard Spinosad; and Captain

Jack’s Dead Bug Brew).

Spinosad is an organic control that is very effective on this pest.

Thorough spray coverage of foliage is essential for good control with

any of these products. (Ward Upham)

 

Bristly Rose Slug

This insect has been skeletonizing rose leaves Salina and Manhattan

areas. This is not a caterpillar but is the larva of a sawfly. Close

examination of this small (½ inch) larva will reveal very fine, hairlike

spines in clusters.

Young larvae will remove the green layer of a leaf leaving behind a

clear material. As the larvae mature, they make holes in the leaf and

eventually may consume all of the leaf but the major veins.

Since these insects are not caterpillars (larvae of moths or

butterflies), BT, found in Dipel and Thuricide will not be an effective

treatment. However, a strong jet of water will dislodge the slugs and

make it difficult for them to return to the plant. Other effective

treatments include insecticidal soap, horticultural oils, spinosad

(Natural Guard Spinosad, Monterey Garden Insect Spray or Captain Jack’s

Deadbug Brew) and permethrin (Eight Vegetable, Fruit and Flower

Concentrate; Hi-Yield Lawn, Garden, Pet & Livestock Insect Spray). (Ward

Upham)

 

Jumping Oak Galls

We have several reports of jumping oak galls. Leaves of the white

oak family show small spots or bumps that eventually fall out and leave

a hole about the size of the head of a pin.  The fallen galls attract

attention by jumping an inch or more due to the action of the larva

inside the gall.

Jumping oak galls are caused by a very small, stingless wasp that

lays eggs on developing oak leaf buds early in the spring. The larva

that hatches from the egg will start to feed and juices from the saliva

will cause the gall to form. The larva will feed inside the gall which

offers a measure of protection. The galls are quite small; about the

size of a pinhead. The gall eventually drops out of the leaf and falls

to the ground. The galls will then jump due to movement of the larva

inside the gall. This helps the insect move into the litter under the

tree or into cracks in the soil where the insect will eventually pupate

and overwinter. The mature wasp will chew its way out of the gall the

next spring to start the cycle over again.

White oaks and members of the white oak family can be affected.

Though heavy infestations can cause leaves to brown (or turn black),

curl and possibly drop, otherwise healthy trees are not appreciably

harmed. Even if it were more serious, it is too late to treat by the

time symptoms are seen. Often natural controls prevent damage in

subsequent years. Keep trees healthy by watering during dry weather.

(Ward Upham)

 

MISCELLANEOUS

After-Effects of Too Much Rain

Many areas of Kansas have had saturated or near-saturated soils for

several weeks now. Gardeners are likely to assume that watering won’t be

needed for quite some time after dry weather arrives due to such high

soil moisture levels. Actually, watering may be needed much sooner than

you expect.

Excessive rain can drive oxygen out of the soil and literally drown

roots. Therefore, as we enter hotter, drier weather, the plants with

damaged root systems may be very susceptible to a lack of water. Don’t

forget to check your plants for signs of wilting or leaf scorching and

water as needed.

If irrigation is called for, water deeply and infrequently. Usually

once per week is sufficient depending on the weather. Soil should be

moist but not waterlogged. (Ward Upham)

 

Contributors:  Jeff Whitworth, Entomologist; Holly Davis, Entomologist;

Ward Upham, Extension Associate

 

Division of Horticulture

1712 Claflin, 2021 Throckmorton

Manhattan, KS 66506

(785) 532-6173

 

For questions or further information, contact: [email protected] OR

[email protected]

This newsletter is also available on the World Wide Web at:

http://hnr.k-state.edu/extension/info-center/newsletters/index.html

The web version includes color images that illustrate subjects

discussed. To subscribe to this newsletter electronically, send an

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address in the message.

 

Brand names appearing in this newsletter are for product identification

purposes only. No endorsement is intended, nor is criticism implied of

similar products not mentioned.

K-State Research and Extension is committed to making its services,

activities and programs accessible to all participants. If you have

special requirements due to a physical, vision or hearing disability, or

a dietary restriction please contact Extension Horticulture at (785)

532-6173.

Kansas State University Agricultural Experiment Station and Cooperative

Extension Service K-State Research and Extension is an equal opportunity

employer.  Issued in furtherance of Cooperative Extension Work, Acts of

May 8 and June 30, 1914, as amended. Kansas State University, County

Extension Councils, and United States Department of Agriculture

Cooperating, Ernie Minton, Acting Dean.

 

Christy Dipman

Horticulture & Natural Resources, KSU

1712 Claflin

2021 Throckmorton Plant Science Cntr.

Manhattan, KS 66506

(785) 532-6173

[email protected]

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