July 2021 Horticulture Tips

Thursday, July 1, 2021

Oklahoma Pecan Update, July 9

Becky Carroll, Associate Extension Specialist, Fruits and Pecans

Leaf sampling, Pecan Development and Weevil are the topics planned for discussion on July 9 at 1pm. The pecan webinar is open to anyone with an interest in pecans - homeowners, hobbyists and commercial growers including extension educators. In-service credit is available to extension personnel.

Dr. Phil Mulder will be discussing weevil and late season insects. This will likely be Phil’s last pecan zoom since he is retiring. Dr. Lu Zhang will be talking about pecan development and some of her work that she is conducting. Becky Carroll will explain leaf sampling for fertilizer recommendations and give a few updates from around the state.

After registering, you will receive a confirmation email containing information about joining the meeting.

Information and recordings of previous sessions are available on the Oklahoma Pecan Management webpage or the Oklahoma Pecan Management Facebook page - @okpecans.

Questions can be emailed to becky.carroll@okstate.edu.

Summer is for Fall Harvest

David Hillock, Consumer Horticulturist

Summer may not seem like the best time to be thinking about a fall garden, but July through September is the time to start planting several vegetable varieties in order to have a fall harvest. Some tender vegetables that can be started in July and August and harvested before fall frosts include beans, cilantro, sweet corn, cucumber, pumpkin, and summer and winter squash. Be sure to choose varieties that mature early and are disease resistant. Some semi-hardy plants, those that may continue to grow and be harvested after several frosts, include beet, broccoli, cabbage, carrots, garlic, leaf lettuce, parsnip, and radish.

Climatic conditions of July and August involve high soil temperature, high light intensity, and rapid drying of the soil, resulting in an increase in the problems of obtaining a uniform stand of plants. Achieving a full stand of plants in the heat of summer may require special treatments. This might include shade over rows when seeded and supplemental watering to reduce soil temperature and aid in seed germination.

Insects and weeds can be more prevalent this time of year so check frequently for insect activity and weed growth and use appropriate control measures. For more information on planting a fall garden see OSU Extension Fact Sheet HLA-6009 Fall Gardening.

Fall Gardening

Casey Hentges, Oklahoma Gardening Host and Laura Payne, Assistant Producer, Oklahoma Gardening

As August approaches, many of the plants have been producing for quite some time now and may start to look a bit tattered. However, August is a good time to consider cleaning out the summer plants and starting a fall garden.

While fall gardening has never been as popular as spring gardening, some gardeners say it is easier. Although fall gardening does require getting plants established during the heat of the season, plants will be able to continue to grow and produce as the temperatures become milder.

Winter squash is a good vegetable to start late July into the first week of August as it needs about 100-120 days until harvest. Another round of summer squash and cucumbers can also be started during this time since they typically only need 40 – 50 days until harvest. Beans, cowpeas, and pole beans can also be planted during this time frame. However, lima beans and bush beans can be planted until around August 20.

Finally, any tomato plants that are looking healthy in July may still produce fruit but not as prolific as they did before the high temperatures of summer. When daytime temperatures are above 85 – 90 degrees and 75 degrees at night, the pollen becomes less viable. The plants may still flower but not progress into fruits. As fall approaches and the temperatures cool down, the tomatoes should start producing again.

OPGA Annual Meeting Award Winners

Becky Carroll, Associate Extension Specialist

Over 190 pecan growers from all over Oklahoma and many surrounding states attended the 2021 Oklahoma Pecan Growers Convention & Trade Show on June 10-12 in Broken Arrow. Many thanks to all those that attended and assisted with the program.

The 2020 State Pecan Show winners were announced during the banquet on Friday evening. Top award winners were:

Best of Show – Pawnee exhibited by Ray Purdy, Kay county - 58.3 % Kernel 43.1 nuts/lb
Champion Native – Joe Ihle, Creek county - 56 % Kernel 77.2 nuts/lb
Largest Pecan – Mohawk exhibited by Dick Hoffman, Payne county - 32.9 nuts/lb
Highest % Kernel – Peruque Dick Hoffman, Payne county - 60.4 % Kernel

Other special awards presented went to:

Herman Hinrichs Award – Charlie Graham, Noble Research Institute
Grower of the Year – Chad Selman, Skiatook, OK
Grove of the Year – Joe Ihle Orchard, Edna, OK
Special awards (retirement) to Phil Mulder, Steve Upson, and Becky Cheary.

Dr. Phil Mulder recognized at OPGA 2021 Annual on his retiremenet.

Dr. Thomas Coon, Dr. Phil Mulder and OPGA President Chad Selman congratulating Dr. Mulder on his upcoming retirement. Additional photos of the events can be found on the @OklahomaPecanGrowersAssociation Facebook page.

Fruit Splits and Cracks, are they Diseases or Disorders?

Becky Carroll, Associate Extension Specialist, Fruits and Pecans

With fruit production, few things can be more disappointing than to miss the late freezes, avoid diseases and insects and then to lose the crop to “Too much water”! This disorder occurs after a period of dry weather with limited soil moisture followed by a big influx of rainfall or irrigation. On those trees without irrigation, there is little that can be done to avoid these problems. Maintaining ideal soil moisture throughout the season is the best defense to avoid this disorder.

Clay soils can often make the issue worse. Heavy, poorly drained soils can hold more water and cause an increase in this disorder. Sandy, well-drained soils will not display this issue as often, but it can still occur on those lighter soils as well.

Peaches are commonly seen with splits, but this in 2021, cherries and Asian pears have displayed this issue. It can also occur on apples and other fruits, and even on pecans.

Normally the split area is not too deep. The fruit is still edible but these breaks in the skin open up the fruit to insects and diseases in some cases.

In 2019, these Redhaven peaches split due to heavy rainfall during the ripening stage.

Stella cherries growing on heavy soils, showed splitting in late May 2021 and by the time they were ripened a week later, insects like flower scarobs, wasps and flies had made the fruit inedible.

This week, Drippin’ Honey Asian Pears started exhibiting splitting after 6 to 7 inches of rainfall in Lincoln County. The abundance of rain had followed a period of dry conditions.

July Irrigation

David Hillock, Consumer Horticulturist

While we have recently received ample amounts of rainfall, eventually it will get drier as the summer continues. Adequate soil moisture is essential for good crop growth. A healthy plant is composed of 75-90% water, which is used for the plant's vital functions, including photosynthesis, support (rigidity), and transportation of nutrients and sugars to various parts of the plant.

There are several options for applying water to plants. These include: a watering can, a garden hose with a breaker nozzle or spray attachment for containers, small gardens or individual plants and portable lawn sprinklers, a perforated plastic soaker hose, drip or trickle irrigation, or a semi-automatic drip system for lawns and gardens.

Your careful use of irrigation techniques will help local streams and will ultimately benefit larger bodies of water in your surrounding area by reducing fertilizer and pesticide run-off and by conserving water.

Some Basic Techniques and Principles for Watering

Adjust the flow or rate of water application to about one-half inch per hour to avoid causing run-off. To determine the rate for a sprinkler, place small tin cans at various places within the sprinkler's reach and check the level of water in the cans at 15-minute intervals.

When using the oscillating type of lawn sprinkler, place the sprinkler on a platform higher than the crop to prevent water from being diverted by plant leaves. Try to keep the watering pattern even by frequently moving the sprinkler and overlapping about one half of each pattern.

Do not sprinkle foliage in the evening. Wet foliage overnight may encourage disease. Morning watering is preferred.

Perforated plastic hoses or soaker hoses should be placed with holes down (if there are holes), along one side of the crop row or underneath mulch. Water will slowly soak into the soil.

Frequent, light watering will only encourage shallow rooting, causing plants to suffer more quickly during drought periods, especially if mulches are not used. On the other hand, too much water, especially in poorly drained soils, can be as damaging to plant growth as too little water.

Your lawn can use an inch or more of water per week in hot, dry weather, The lawn should be watered when the soil begins to dry out, but before the grass wilts. loss of resilience can be observed; footprints will make a long-lasting imprint instead of bouncing right back.

Critical watering periods for selected vegetables are:

Asparagus: Spear production, fern development
Broccoli, Cabbage, Cauliflower: Head development
Beans, Peas: Pod filling
Carrot: Seed emergence, root development
Corn: Silking, tasseling, ear development
Eggplant, Tomato: Flowering, fruiting
Cucumber, Melon: Flowering, fruit development
Lettuce: Head development; moisture should be constant

Heat Safety

Lynn Brandenberger, Extension Specialist

Why is heat a problem? Well, let’s face it, most of us are spoiled. We likely work inside in an air-conditioned building and when we are at home we have a climate controlled home too. As a result, many of us are not acclimated to the high temperatures of summer.

So. . . What should we do? First begin to understand the intricacies of the human body. Did you know that humans are the most heat tolerant and adaptable creatures on earth? Wow, what in the world does that mean? Well for starters our bodies will adapt to heat over time (2-3 weeks) allowing us to tolerate much higher temperatures than we were able to on the first hot day of the summer. Be certain to ease into summer for the first couple of weeks during high temperatures so your body has time to adapt. No other creature in nature has the super-powers that we have for heat adaption. Over time levels of water and salt change in our blood to increase our ability to cool ourselves. Next, blood vessels adjust to bring more blood to the surface of the skin which also allows for better cooling. For more information check out the article on “How to handle the heat (with science)".

Second, realize that staying hydrated is critically important. We need a minimum of three liters of water per day when working outdoors during summer. Notice I said water, not sugary soft drinks. You can tell if you are adequately hydrated by keeping track of your water intake and output. If urine is clear or slightly yellow then you are probably drinking enough water, if on the other hand urine is dark or coffee colored then you need to drink more water.

Signs of both dehydration and heat exhaustion/stroke include a flushed color (your face turns bright red), nausea, headache, not sweating, and loss of consciousness. The signs listed above are given from early signs to severe signs of heat exhaustion/stroke. Personally, my face turns red very soon, but I understand that is how I’m made and it doesn’t concern me. Once I move onto feeling nauseated I understand that I need to move to the shade and start drinking more cold water to bring my temperature down. Being familiar with these signs should help you to “tune” your thought processes so you know what is happening to your body related to heat and respond accordingly.

What should you do if you or someone else is showing the signs of dehydration and heat exhaustion/stroke? First and most important, cool the person down as quickly as possible, move to the shade, drink cold water, hose them down with tap water and fan them by hand or with an electric fan. If the person does not respond quickly or if they are unconscious call an ambulance and have them transported to the Emergency Room or other medical care as soon as possible.

Bagworms

David Hillock, Consumer Horticulturist

As I have been walking around lately, I have noticed bagworms are beginning to pop up all over. They are commonly found on juniper and arborvitae species, which seems to be some of their favorite plants, though they can be found on several other species as well. I even found several on a small potted bald cypress on my back patio the other day.

Bagworms are a species of clear winged moths. The adult male develops into the moth and the female are wingless, have no functional legs, eyes or antennae, are almost maggot-like in appearance and will never leave the bag. The bags are quite tiny right now but will continue to grow as the larvae add fragments of the host plant foliage while they feed. The larvae remain in the bag, moving the bag across the twig as they feed and grow.

Now is the time to control them. Hand picking and destroying each little bag is the most effective way to manage them if you can reach them. If they are out of reach, several pesticides are labeled for control and are quite effective at this very young stage of the insects’ life. If you wait until they get more mature the insecticides used will be less effective.

Bacillus thuringiensis var. kurstaki (B.t.), a bacterial insecticide, is reported to provide good control of young bagworms. Also effective are products that contain the active ingredient Spinosad. These insecticides must be ingested by the caterpillars to achieve kill, so be patient as it will take some time to see results. Repeat applications may be needed later in the summer to keep susceptible plants free of bagworms.

Late in the season, large, older larvae are not as susceptible to B.t. and spinosad. Thus, bagworms must be sprayed with broad-spectrum, contact insecticides. Homeowners can look for products containing the active ingredients carbaryl (Sevin) or malathion that are labeled for caterpillar control on ornamental plants. An arborist certified with the International Society of Arboriculture (ISA) should be hired to combat bagworm infestations on large trees with tall canopies. Contact your county extension office for assistance with locating an ISA-certified arborist in your area.

Remember, now is the time to control them by either hand picking or applying an insecticide while the worms are small. If not controlled, bagworms can completely defoliate a plant, which usually kills a host plant like juniper. Broadleaf plants are not killed but may be weakened leaving them more susceptible to attack from other pests.