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Blog Post: http://www.ksuhortnewsletter.org
Video of the Week: Dividing Iris
https://kansashealthyyards.org/all-videos/video/dividing-iris
UPCOMING EVENTS
Kansas Turf & Ornamentals Field Day
The Kansas Turf & Ornamentals Field Day will be held Thursday, August 3 at the K-State Research Center in Olathe (35230 W. 135th).
The field day program is designed for all segments of the turf & ornamentals industry – lawn care, athletic fields, golf courses, landscape, nursery, 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.
One hour of pesticide recertification credit in both 3A and 3B are available, as well as GCSAA education points.
For a copy of the program and to register to attend, go to https://www.kansasturfgrassfoundation.com/
REMINDERS
1. Deadhead annual flowers that need it.
2. Spray sweet corn for corn earworm if silks haven’t turned brown yet.
3. Take soil test if establishing or overseeding a lawn this fall.
VEGETABLES
Anthracnose on Cucumbers
Description: Anthracnose is a disease caused by a fungus which is most severe in cucumbers, muskmelons and watermelons. Anthracnose survives in plant debris and seeds. Infected leaves and fruit develop spores that spread easily when water splashes on them or when contact is made such as with hands or tools. Anthracnose favors warm, moist conditions.
Damage: Infected leaves exhibit irregularly shaped brown spots that may have a hole in the center. Stems may become elongated and sunken when infected.
Control: Begin with resistant varieties and purchasing clean seed from a reputable distributor. Do not collect seed from infected plants. Practice crop rotation allowing three years between crops from the squash family. Avoid splashing soil and water on the plants by using mulch and drip irrigation. Infected plants should be destroyed, not composted. Sanitize tools between use if they contact diseased plants.
Periodic fungicide applications may be necessary during wet weather in mid-summer. Apply chlorothalonil (Bonide Fungonil Concentrate, Daconil, Ortho Garden Disease Control, Fertilome Broad-Spectrum Landscape and Garden Fungicide, others) or mancozeb (Bonide Mancozeb Flowable). (Cynthia Domenghini)
PESTS
Pine Needle Scale Control Window Approaching
Description: Pine needle scale appears as white, oblong shapes on pine needles. Beneath the protective scale covering dwells the insect. The waxy covers over females are about 1/3-inch long and have a yellow tip at the front end which is narrower. Adult females are about 1/8-inch long, orange-red in color and do not have wings. The scale coverings over males are smaller and solid white. Adult males are 1/25-inch long and develop one set of wings at maturity. Eggs are reddish-brown and very small. Crawlers that hatch from the eggs are oval-shaped and light purple to reddish-brown. They are so small a magnifying lens is sometimes required to see them.
Life Cycle: Females and eggs overwinter under the protection of the waxy scale. Females may lay up to 40 eggs beneath the cover. Crawlers emerge from the eggs in the spring to find a new feeding location. When feeding begins, the crawlers create a new covering to protect them by secreting a waxy substance. Within a couple of months, the crawlers reach maturity and mating begins. Males die after mating. Females lay eggs mid-summer giving rise to the second generation which reach maturity in early fall.
Damage: Scale feeds by piercing the pine needles and sucking out sap. Needles may become mottled in color and eventually turn brown. A severe infestation may cause the branches to dieback or may kill the tree entirely.
Control: Maintain healthy trees by monitoring for scale crawlers late spring to early summer (first generation) and again mid- to late-July (second generation). Wrap double-sided tape around the needles or twigs of the pine tree to monitor for the crawlers. Electric tape smeared with petroleum jelly can trap the crawlers. Use colored tape so the white bodies are easier to see.
When crawlers are present it is time to spray. Some effective insecticides include: acephate (Acephate, Orthene), cyfluthrin (Tempo, BioAdvanced Vegetable & Garden Insect Spray), and permethrin (38 Plus Turf, Termite & Ornamental Insect Spray; Eight Vegetable, Fruit & Flower Concentrate or Garden and Farm Insect Spray). Insecticides must be applied soon after crawlers emerge to be effective. Once they are protected beneath their waxy cover insecticides will not be able to reach them. (Cynthia Domenghini)
FRUIT
When to Harvest Grapes
Waiting for grapes to ripen takes extra patience as the color matures before the rest of the fruit. Harvesting based on color alone will likely leave a bitter taste in your mouth as it takes several more weeks for the sugars to reach their peak and the tartness to subside. Waiting for the fruit to fully develop is important since grapes do not continue to ripen after harvest.
Prior to harvest look for a whitish coating on the grapes. This is an indicator of ripeness. Fully ripe grapes are usually slightly less firm than unripe fruit. Open one of the grapes and observe the seed color. Seeds of ripe grapes often change from green to brown. Finally, if all other measures indicate the grapes are ripe, do a taste test to make the determination.
Grapes can be stored for up to eight weeks at 32 degrees F with 85 percent relative humidity. They can also be processed into jams and jellies. (Cynthia Domenghini)
Prop Up Fruit Tree Limbs if Needed
Heavy fruit loads this season may cause limbs to break if they are not given extra support. As fruits increase in size, the additional weight on individual branches may be substantial. One-inch thick boards that are 4 inches wide can be used to prop up limbs. You may wish to use two boards that overlap so the amount they overlap can be adjusted to change the total length of the board. Two to three screws can hold the two boards together. Cut a “V” on the top edge of the board on which the limb will rest so that it doesn’t slip off. Long limbs that are heavily loaded with fruit may need a prop in the center and another to support the outer part of the limb.
A plastic belt-like material that is about 2 inches wide may also be used. This can be tied to a heavily loaded limb, then to a large diameter limb above for support. Where a large limb is used for support, it is good to have it supporting limbs on opposite sides so the weight is balanced.
Another solution is to wrap a tape or belt material around the tree in a spiral to prevent limbs from bending until they break. Heavy twine may be used, but it should be removed when the fruit is picked or soon after so it does not cut into the bark on the limb.
Check trees regularly, up to two times a week during the last month the fruit are maturing. You will find additional limbs that need support. Tending to the heavily loaded tree limbs will reduce the number of broken limbs and help keep a balance of the fruiting wood in your tree. Next year, prune long, weak branches back to a side branch to help prevent this problem. (Ward Upham)
MISCELLANEOUS
Dividing Iris
Irises develop from the rhizome root system. Every year, each rhizome yields additional rhizomes creating a larger network of roots. After several years of this development, bloom production may slow down or halt altogether when the rhizomes become too crowded. This indicates it’s time to divide the rhizomes.
When the bloom season has ended dig the entire plant including all the rhizomes. Break the rhizomes apart by hand at the joints where they are connected. Healthy rhizomes should have roots extending below and a fan of leaf blades above. The rhizome should be at least the width of your thumb and firm. Discard any rhizomes that do not have leaf fans protruding as well as any rhizomes that are soft and have an odor.
Trim the fan blades to about eight-inches cutting each blade at an angle to keep water from collecting in the thick, open leaves. Trimming the leaves prevents the plant from falling over until the roots become established. Dig a shallow hole, deep enough that the top of the rhizome is slightly exposed. Irises will tolerate poor soil conditions but well-drained soil is best. Space plants 12 to 18-inches apart and do not mulch. Irises do not respond well to over-watering; however newly planted rhizomes do need to be watered in thoroughly.
Fertilize according to soil test recommendations or by applying a complete fertilizer, such as a 10-10-10, at the rate of 1 pound per 100 square feet. Mix the fertilizer into the soil to a depth of 6 inches. If your soil test shows high phosphorus levels, use a fertilizer that has a much higher first number (nitrogen) than second (phosphorus). It is important to get irises planted early enough in the season to allow roots to establish before the first hard frost. (Cynthia Domenghini)
Peonies with the “Measles” and Powdery Mildew
It’s the time of year when these two fungal diseases may begin to appear on peony plants in the landscape. Some preventative care each year is the best control against them.
Peony measles is also referenced as red spot and leaf blotch. Initially, purplish-brown circular spots appear on the top of the leaves. On the underside, the spots appear brown. Over time, more spots develop and eventually merge creating large, irregularly shaped blotches. Spots can appear on the stems, flower buds, petals and seed pods as the disease progresses.
Powdery mildew can infect a variety of plants. It presents as a white-grey powder on plant material. Powdery mildew is quite common in Kansas due to the warm, humid conditions.
Fortunately, both diseases are primarily aesthetic problems unless they become severe. Promote good air flow by spacing peonies several feet apart when planting. Individual plants can be pruned selectively during the growing season to improve circulation. Powdery mildew and measles overwinter in the soil on diseased plant material. At the end of the growing season cut peonies to the ground and throw out the plant material. Do not compost, especially if the plants are diseased. Use drip irrigation, if possible, to keep water from splashing on the leaves. When leaves are wet, avoid handling them. (Cynthia Domenghini)
Contributors:
Cynthia Domenghini, Instructor ([email protected])
Ward Upham, Extension Associate ([email protected])
Division of Horticulture
1712 Claflin, 2021 Throckmorton
Manhattan, KS 66506
(785) 532-6173
For questions or further information, contact: [email protected] OR [email protected]
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Cooperating, Ernie Minton, Dean.
