Blog Post: http://www.ksuhortnewsletter.org Video of the Week: Controlling Bagworms
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
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)
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 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
* 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
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)
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
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:
permethrin (38 Plus Turf, Termite & Ornamental Insect Spray; Eight
Vegetable, Fruit & Flower Concentrate; Lawn, Garden, Pet, & Livestock
cyfluthrin (BioAdvanced Vegetable and Garden Insect spray)
bifenthrin (Bug Blaster II, Bug-B-Gon Max Lawn and Garden Insect
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
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.
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
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
For questions or further information, contact: [email protected] OR
This newsletter is also available on the World Wide Web at:
The web version includes color images that illustrate subjects
discussed. To subscribe to this newsletter electronically, send an
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)
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.
Horticulture & Natural Resources, KSU
2021 Throckmorton Plant Science Cntr.
Manhattan, KS 66506