Garden Tips for August
David Hillock


  • August is a good month to start your fall vegetable garden. Bush beans, cucumbers, and summer squash can be replanted for another crop. Beets, broccoli, carrots, potatoes, lettuce, and other cool-season crops can also be planted at this time. (HLA-6009).
  • Soak vegetable seed overnight prior to planting. Once planted, cover them with compost to avoid soil crusting. Mulch to keep planting bed moist and provide shade during initial establishment. Monitor and control insect pests that prevent a good start of plants in your fall garden.

Fruit and Nut

  • Continue protective insect applications on the fruit orchard. A good spray schedule is often abandoned too early. Follow directions on last application prior to harvest. (EPP-7319)


  • Towards the end of the month, divide and replant spring-blooming perennials like iris, peonies, and daylilies if needed.
Trees and Shrubs
  • Discontinue deadheading roses by mid-August to help initiate winter hardiness.
  • Watch for second generation of fall webworm in late August/early September. Remove webs that enclose branches and destroy; or spray with good penetration with an appropriate insecticide.

Lawn and Turf

  • Grassy winter weeds like Poa annua, better known as annual bluegrass, can be prevented with a preemergence herbicide application in late August. Water in the product after application. (HLA-6420)
  • Areas of turf with large brown spots should be checked for high numbers of grubs. Mid-to-late August is the best time to control heavy white grub infestations in the lawn. Apply appropriate insecticide if white grubs are a problem. Water product into soil. (EPP-7306)
  • Tall fescue should be mowed at 3 inches during the hot summer and up to 3 ½ inches if it grows under heavier shade. (HLA-6420)
  • For areas being converted to tall fescue this fall, begin spraying out bermudagrass with a product containing glyphosate in early August. (HLA-6419)
  • Irrigated warm-season lawns can be fertilized once again; apply 0.5 lb N/1,000 sq ft in early to mid August.
  • Brown patch of cool-season grasses can be a problem. (HLA-6420)


  • Water compost during extremely dry periods so that it remains active. Turn the pile to generate heat throughout for proper sterilization.
  • Always follow directions on both synthetic and natural pesticide products.
  • Watch for high populations of caterpillars, aphids, spider mites, thrips, scales and other insects on plant material in the garden and landscape and treat as needed. (EPP-7306)
  • Water all plants thoroughly unless rainfall has been adequate. It is better to water more in depth, less often and early in the morning.

Soil Testing

David Hillock

Healthy plants require a healthy soil. One way to determine the ability of your soil to sustain plants is to take a soil test.

When and How Often to Soil TestSoil testing should be viewed with the same approach as one would take toward servicing the lawn mower or car engine. If we do not know how much gas and oil are present, we check the fuel gauge and dip stick. If we want to know whether or not soil pH, available phosphorus and available potassium exist at desirable levels we need to test the soil. Since these soil properties do not change much from one year to the next, it is not necessary to soil test the same area each year. However, a soil test once every three years will provide information needed to manage a lawn and garden properly.

Plant-available nitrogen in the soil changes considerably from year to year and even within a season. Plant growth, addition of nitrogen fertilizer and decay of organic matter will all cause significant changes in available nitrogen in just a few days. It is not necessary to soil test each year or within the season to closely monitor nitrogen needs. Instead, add small amounts of fertilizer nitrogen throughout the growing season, or aerate the soil by shallow cultivation to promote the release of organic nitrogen to improve plant growth or green color.

Collecting a Representative Soil SampleHomeowners and lawn care professionals must realize the spatial variability existing around the yard when collecting a soil sample. Each sample collected should represent the area to be fertilized. The fertility level in the vegetable garden may be different from that of a flower bed. Soil test parameters in the front yard may be drastically different from those in the backyard. Therefore, separated samples may need to be collected from those areas so they can be treated differently. Avoid sampling “odd-ball” areas. A core or slice from the surface to a depth of 6 inches should be taken from 15 to 20 locations in each area and composited into one representative sample for testing.

Soil samples may be submitted to the county Extension office. They will send the samples to the Soil, Water and Forage Analytical Laboratory for testing, and then send the results back to you with fertilizer recommendations. Soil samples are analyzed routinely for pH, nitrate nitrogen, plant available phosphorus and potassium, while secondary and micronutrients are tested on request. A number of other tests such as soil organic matter content and texture are also available through the lab.

Pecan Crop Load Thinning Field Day Scheduled for August 9

Becky Carroll

On Tuesday, August 9 a Pecan Crop Load Thinning field day will be held at the Cimarron Valley Research Station near Perkins. The meeting is scheduled from 4-6pm.  The Oklahoma Pecan Growers’ Association, OSU Horticulture & Landscape Architecture Department, The Samuel Roberts Noble Foundation and the OSU Field & Research Service Unit will sponsor the event. Attendees will get the opportunity to learn about the thinning process and then see the equipment in action in the field. We will discuss the benefits of thinning, when to thin, and the equipment needed as well as hear some tips from experienced commercial pecan growers. 

At the conclusion of the meeting, participants are invited to stay for grilled hamburgers and a time to visit and ask questions. This is a free event for anyone interested in growing pecans.

The Cimarron Valley Research Station is located at 10820 S. Jardot in Perkins. It is ½ mile north of Hwy 33 and 177 intersection (north of Sonic). For more information contact or 405-744-6139. 

Pecan Crop Load Thinning Time

Becky Carroll

pecan_crop_thinningAlthough pecan crops may be spotty in some areas due to heavy crops last year, many pecan growers with improved varieties should be checking crop loads to determine if they need to mechanically thin their pecans. On the largest fruited pecans such as Mohawk and Maramec only about 45-50% of the terminals should have clusters, medium-large sized like Pawnee, 50-60% and on smaller varieties, like Kanza, 60-70% of terminals can be fruiting. If more terminals are fruiting than recommended, the pecans should be thinned.

Crop load thinning is usually done the first week or two of August or more specifically when the pecans are in the water stage when the ovule has expanded between 50-100%, (see figure and picture below). Just as peaches and apples are thinned, pecans will greatly benefit from crop load management. Thinning the fruit will increase fruit quality, help reduce alternate bearing, as well as reduce the possibility for and severity of winter freeze damage. Many growers have said that they should have reduced their crop last year especially on Pawnee because they have little to no crop of Pawnee this year.

Pecans can be mechanically thinned with a conventional shaker fitted with donut pads. Be sure to keep the underneath of the flaps on the donut pads greased to help limit barking the trees. Fact Sheet HLA-6251 Pecan Crop Load Management details the procedure

The drawing shows a pecan cut longitudinal exposing the ovule at 50% expanded. The picture is a Kanza pecan cut on July 27, 2016 showing the ovule expanded to about 60%

Pecan Weevil Monitoring

Becky Carroll

Weevil traps should be placed in the orchard at this time.  The Circle trap is the preferred trap for monitoring weevil emergence.  Fact Sheet EPP-7190 Monitoring Adult Weevil Populations in Pecan and Fruit Trees in Oklahoma explains how to construct and when and where to place the traps ( With the recent rains, weevil will be emerging and feeding on nuts until the dough stage when they start laying eggs in the pecans.  Have a plan for weevil control and be ready to spray to prevent losses. When pecan crops are small, weevil feeding will add to the reduction in the crop. When weevils feed on the nut early, the nuts usually fall to the ground. Growers will need to assess when they should start protecting their crop. Each orchard will be different. With heavy crops, weevil feeding may not be too detrimental during the water stage, but once the fruit begins to change stages, growers will want to try to eliminate the egg laying phase that will reduce quality and prices.

Managing Vegetables in Challenging Seasons

Lynn Brandenberger

One great thing about producing vegetables is that you just never know what will happen during a given season.  I say that tongue-in-cheek because it can be frustrating to do our best and then be denied the bountiful harvest that we are hoping for, but that’s what keeps us excited when things work out well. 

We’ve been receiving plenty of phone calls and e-mails regarding problems that folks are having in gardens and commercial vegetable fields.  A lot of those calls are related to disease problems, some insect and mite issues also.  That said I’d like to travel back in time to pre-season and help you lay a foundation of preventative actions that can reduce the potential for pest problems, who knows maybe next season you’ll have better luck.

First, soil condition and fertility are a large part of plant health.  Think about it this way:  If we as people are malnourished and stressed what happens?  We get sick!  So do your vegetable crops!!  Making the effort to have a soil test completed and to follow fertility recommendations and to also improve the soil with additions of organic matter can go a long way toward improving the ability of any crop to tolerate and overcome pests.

Second, think ahead about what you can do to anticipate pests.  Familiarize yourself with potential crop pests, use crop rotations, clean up the garden or field following a cropping season, planting a cover crop are all cultural ways to prevent a buildup of pests be it disease, insect or weed pests.  Consider which pests are perennial problems for your field or garden i.e. squash bugs, spider mites, fungal or bacterial diseases, weeds or whatever. Become familiar with when these pests usually show up and what types of alternatives you have available for their control.  Control measures can include a number of things such as pest resistant varieties, seed-treatments, drip irrigation and mulching to reduce soil being splashed onto the crop, exclusion materials such as floating row-covers.  Just spend some time exploring the possibilities.

Next, come up with a battle plan for the growing season.  Don’t wait until it’s a big problem before you have ideas of how to deal with challenges.  Example: Last year we had extremely high populations of squash bug in our pumpkin plots.  Although we were successful in managing this pest we took preventative measures after the season and immediately cleaned up the area with tillage and then planted non-host winter cover crops to prevent the over-wintering of this pest.  This year we are anticipating its arrival, but we have definitely delayed the start of squash bug damage.

Be aware of the tools that you have available for managing pests.  OSU has Extension offices in all counties and these serve as a gateway to a large amount of information and expertise when dealing with crops.  County Extension Educators often will be your one-stop shop for answering your questions and if they need help Extension specialists at Stillwater are available through the county office to assist.  The first step to controlling crop pests is to identify what is causing the damage.  A great resource that is available for pest identification is the Plant Diagnostic Laboratory where you can send photos or samples of pests.  This is a free service for Oklahoma residents and their contact information is on their website at: Additional information about the Plant Diagnostic Laboratory is available from factsheet L-220 “Plant Disease and Insect Diagnostic Laboratory” available on-line at:

Another great place for information on pest management and control are the following OSU Factsheets:

  • EPP 7313 Home garden insect pest control
  • EPP 7625, 7626, 7627 Common diseases of tomato
  • EPP 7640 Solar heating (solarization) of soil in garden plots for control of soilborne diseases
  • EPP 7646 Diseases of asparagus in Oklahoma
  • EPP 7652 Non-chemical methods for control of diseases in home landscape and garden
  • EPP 7666 Diseases of leafy crucifer vegetables
  • EPP 7677 Phytophthora blight of cucurbits and peppers
  • HLA 6431 Earth-Kind Gardening Series: Cultural Control Practices
  • HLA 6007 Improving Garden Soil Fertility
  • HLA 6013 Summer Care of the Home Vegetable Garden

Last, but certainly not least is the need to understand each crop and its growth requirements.  As vegetable producers we have a tendency to try to push the envelope regarding crop scheduling, always going for earlier or later production.  This is critical when we are trying for markets, but can get us into serious trouble with our crop.  I have seen folks push way past the limits, for example:  Okra planted very early before the last frost date.  They may even get a stand, but guess what. . . okra doesn’t grow well in anything close to cool temperatures and the crop usually just sits there and won’t grow until it warms up considerably.  This provides all sorts of opportunities for cool season diseases to move in and attack this cold-stressed warm season crop.  Bottom line, if you want to push the limits of a crops growth season you will need to modify the environment in some fashion i.e. season extension techniques, etc.

In conclusion, you need to understand and provide for the needs of each specific crop, identify and anticipate pest issues and manage those potential problems through control strategies that utilize available tools including cultural controls and other control methods.

 Fall Gardening

David Hillock

Gardening is a year-round activity. Those who garden develop an appreciation and a desire for fresh, nutritious vegetables and fruits. In many situations, the best way to obtain fresh vegetables is to grow them at home.

Some of the best quality garden vegetables in Oklahoma are produced and harvested during the fall season when warm, sunny days are followed by cool, humid nights. Under these climatic conditions, plant soil metabolism is low; therefore, more of the food manufactured by the plant becomes a high quality vegetable product.

Successful fall gardening begins much earlier than the fall season. Factors to be considered are adequate soil preparation, available garden space, crops to be grown, space for each crop, varieties to use, and obtaining the quantity and varieties of seed. Below are some tables to guide you in when and how to start and plant your favorite fall vegetables. For additional information on fall gardening see OSU Extension fact sheet HLA-6009 Fall Gardening.

 Fall Planting Guide

Tender Vegetables (harvest before frost)* Many varieties will do well - select varieties that are early maturing and disease resistant.  Table 1.

Semi-hard vegetable: (May continue to grow and be harvested after several frosts). Many varieties will do well - select varieties that are early maturing and disease resistant.  Table 2.

Pruning Hydrangea

David Hillock

Determining when to prune a hydrangea can be a little confusing sometimes as there are several different species and not all form flowers at the same time. The Bigleaf hydrangea, Hydrangea macrophylla (largely a spring blooming plant) and Oakleaf hydrangea, Hydrangea quercifolia, develop their flower buds on the previous season's growth. Pruning should be done after flowering in the spring. Another note to remember about Bigleaf hydrangea is the flower buds can be damaged during cold, dry winters. This is why they sometimes don't bloom in the spring even though the plant looks pretty healthy.

Smooth hydrangea, Hydrangea arborescens, and Panicle hydrangea, Hydrangea paniculata, bloom in the summer. Flower buds are formed on new growth that season. Pruning can be done on these plants in late winter or early spring.

2017 All-America Selection Winners


All-America Selections is an independent, non-profit organization that tests new varieties than introduces only the best garden performers as AAS Winners.

The AAS Winners offer gardeners reliable new varieties that have proven their superior garden performance in Trial Grounds across North America, thus, their tagline of "Tested Nationally and Proven Locally®". When you purchase an AAS Winner, you know that it has been put through its paces by an independent, neutral trialing organization and has been judged by experts in their field. The AAS Winner label is like a stamp of approval.

Here are a few of the winners for next year to help you plan your gardens. For more information about these and other winners, go to

Celosia Asian Garden 2017 AAS Flower Award Winner
Award Type: National

This spiked beauty claimed victory in North America's trial sites to become the first ever AAS Winner from Japanese breeding company Murakami Seed.

In the garden, Asian Garden celosia continued to bloom on sturdy stems, keeping the bright pink color all summer long, holding up even through some of the first frosts of the season. The AAS Judges commented on the fact that this celosia was a pollinator-magnet, making this AAS Winner a sure bet for pollinator-friendly gardens.

Okra Candle Fire F1 2017 AAS Vegetable Award Winner
Award Type: National

Plants have unique round tapered red pods that can be eaten fresh in salads or boiled. The attractive plant can be grown as an ornamental.

This high-performing AAS Winner received high marks for productivity, taste, texture, and tenderness as well as the ornamental value of red pods on red stems. One judge noted that Candle Fire okra was quite maintenance free to grow, except for the frequent harvesting, which is a great thing! Candle Fire thrives int he heat and is disease resistant even in hot humid climates like the south where it's perfect for traditional fried okra. Suitable for both fruit producing and ornamental usage. Aged fruit can be used in flower arrangements.

Pea Patio Pride 2017 AAS Vegetable Award Winner
Award Type: Regional (Southeast)

A compact snow pea when picked early. Wonderful in containers or planted as small low hedge.

With only 40 days needed to maturity, Patio Pride can be of your first spring harvests, or one of the last fall harvests from your Southeastern garden! This pea is wonderful when planted in containers and is ideal for succession planting yielding a consistent harvest over many weeks. Plant in patio containers with cool season flowers for a beautiful combination ornamental and edible display. Direct seeding is recommended; seed 3-4 every 6 inches then thin to one seedling every 5-8 inches.

Squash, Winter Honeybaby F1 2017 AAS Vegetable Award Winner
Award Type: Regional (Heartland)

Honeybaby produces a large crop of miniature dark orange butternut squash, perfect for home gardeners who want to grow a great tasting and healthy treat in containers.

These shorter vines grow 2-3 feet in a semi-bush habit showing great garden vigor which results in healthier plants that resisted powdery mildew later into the season, especially in the Southeast. Short, wide fruits are slightly larger, sweet and nutty and more meaty than similar comparison varieties. Honeybaby is delicious steamed, baked or made into soups and stews. Plant as soon as soil temperatures reach 65 degrees to ensure maturity in 90-100 days.

Watermelon Mini Love F1 2017 AAS Vegetable Award Winner
Award Type: National

This personal-sized Asian watermelon is perfect for smaller families and smaller gardens. Shorter vines (3-4') still produce up to six fruits per plant and can be grown in smaller spaces. Several judges commented on the crack and split resistant rinds, important for reducing crop loss. For culinary purposes this deep red fleshed watermelon has a thin but strong rind that can be carved into attractive shapes for fruit salad presentations. Mini Love has a high sugar content resulting in sweet and crisp, juicy flesh that will be a true summer delight for watermelon lovers.

Fall 2016 Market Gardening School to take place in Tulsa
Lynn Brandenberger

Providing fresh market producers with the basics on management, production and marketing techniques is what the Market Gardening School is all about. The school is a joint effort between the Samuel Roberts Noble Foundation and Oklahoma State University which have worked together on the course since its inception in 2008. The eight-week course begins August 30 and will meet weekly through October 25 on Tuesday evenings at the Tulsa County Extension Office, 4116 E. 15th St., in Tulsa, Oklahoma. Classes will take place from 6 p.m. to 9 p.m. Registration is $50 per individual or $70 per couple. Couples will receive one set of handouts.

The school is geared toward those who are established in the fresh produce business as well as those who are interested in exploring new enterprises. Each week’s session will focus on a different area related to fruit and vegetable production, such as business planning, soils and fertilizer management, crop establishment and irrigation, guidelines for producing fruit and vegetable crops, season extension, pest management, food safety and marketing. There will be specialists from Oklahoma State and the Noble Foundation teaching each week sharing their knowledge and their expertise during the eight sessions. 

The class is limited to 50 participants and preregistration is required. Online registration is available at . Click on “Short Courses and Schools” once you are at the website. To register by mail, send the registration form from OSU’s Department of Horticulture and Landscape Architecture website at, along with the payment, to Oklahoma Market Gardening School, Attn: Stephanie Larimer, 358 Ag Hall, Stillwater, OK  74078-6027.  If you need more information regarding registration, please call 405-744-5404. 

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