August 2012 / Volume 66            

In This Issue
August Lawn and Garden Tips
Become a Master Gardener
Managing Grasshoppers
Water Collecting with Rain Barrels
Drought Rages On
Ask A Master Gardener

Weather Stats for Gardeners

Soil Temperature 2" below sod:   

86 degrees 


Rainfall total last 30 days:  

0.68 inches


4 Ways to Contact Us
Email us at:

See our website at: 

Call: 918-746-3701 from 9-4, M-F 
Visit us at 4116 E. 15th Street, Gate 6 at the Fairgrounds

Whether you call or bring samples of plants to the office, trained Master Gardeners will answer your gardening questions with science-based information.
Need More Information?

Click on any of the links below:


All about butterfly gardening in Tulsa County 

How to Take a Soil Test

How to collect a good sample of soil from your lawn or garden and get it tested at the OSU lab.
Understanding Your Soil Test Results
Once you have collected your soil test and gotten the results back, now what? Find out here. 
How to Plant a Tree in Oklahoma Soil
Show and tell.
Fescue Lawn Care
12-month maintenance calendar.
Bermuda Lawn Care
Ditto above.
Trees for Tulsa
A list of 50 recommended trees with descriptions.
Crape Myrtles
A list of over 60, by size and color.
Demonstration Garden
Visit our demonstration garden on 
15th Street, open 7 days a week.  
Oklahoma Proven Plants
State horticulturists, nurseries and growers pick favorite plants, shrubs and trees for use in the Oklahoma landscape. See the winners for this year and years past.
Current and historical source of rainfall, air temperatures, soil temps and much more. Click on Bixby station.  

Back Issues  

Past issues of our eNewsletters can be read and downloaded.

Become a Master Gardener

Classes start in September. Register for more information.

Oklahoma State University, in compliance with Title VI and VII of the Civil Rights Act of 1964, Executive Order 11246 as amended, Title IX of the Education Amendments of 1972, Americans with Disabilities Act of 1990, and other federal laws and regulations, does not discriminate on the basis of race, color, national origin, gender, age, religion, disability, or status as a veteran in any of its policies, practices or procedures. This includes but is not limited to admissions, employment, financial aid, and educational services.
August Lawn and Garden Tips


  • If the fall vegetable garden is not yet planted, do so now. For further information, see the Ask a Master Gardener article below.  
  • The hotter and drier it gets, the larger the spider mite populations become! Use powerful jets of water to wash them off plants leaves and spray with horticultural soaps and/or horticultural oils such as Neem. 


  • Irrigated warm-season lawns such as Bermuda and zoysia may be fertilized this month and into early September. Do not fertilize again until spring green-up next year.
  • In the August heat, Bermuda lawns need one inch and fescue 2 inches of water per week. Water lawns 2-3 times weekly trying to wet the ground to 6 inches. Be conscious of any local watering restrictions during the drought.   
  • For areas being converted to tall fescue this fall, begin spraying Bermuda grass with glyphosate products in early-August.

  • Pre-emergent herbicides for winter-annual weed control should be applied between mid-August and Mid-September. A brand containing one of the chemicals dithiopyr, pendimethilin or prodiamine would be an excellent choice. Read and follow the label. They must be watered in to be effective and some will require a second application. Don't use on fescue if you plan on reseeding in September.
  • Mowing heights for fescue lawns should be 3" during summer months, 2 1/2 inches for Bermuda lawns. See Master Gardener lawn care documents in this calendar.


  • Water all plantings thoroughly unless rainfall has been adequate. Expect some leaf fall, a normal reaction to drought.
  • Divide and replant spring blooming perennials, including crowded bearded iris.
  • Hedges and shrubs can be pruned, if necessary, about mid-August. Don't prune spring blooming shrubs, such as azaleas now.
  • Discontinue dead-heading roses by mid-August to help initiate winter hardiness.
  • Fall webworm in late-August/early-September may be a problem, contact Master Gardeners for recommendations. 

Are You Interested in Becoming
a Master Gardener?  
demo front yard

If you enjoy gardening, learning about gardening and have an enthusiasm for sharing your knowledge with others, the OSU Tulsa County Master Gardener program may be for you.


The training program for new Master Gardeners is offered once yearly beginning in September. For those interested in the program, orientation lectures will be held at 10:00 am on August 4 and repeated at 1:00 pm on August 15 at the Tulsa County OSU Extension Center at 4116 E. 15th street (gate #6 into the fairgrounds off of 15th).


These orientation sessions will review the Master Gardener program and requirements to enter this year's class. This includes costs for the classes and agreement for volunteer hour participation after training is completed.


Following orientation, an interview may be scheduled and if you are accepted into the program, the first class is September 8th, with other classes each subsequent Wednesday through December 8th. There are over 70 hours of instruction offered by OSU faculty and extension horticulturists.


These classes will give you a good background in horticulture and prepare you to confidently deal with most gardening problems. Not only will you learn a lot, but you will make many new friends and join the group of over 300 active Tulsa County Master Gardeners.


No previous horticultural training or education is required to enter the Master Gardener program-training starts with the basics. Come to the orientation and learn about the program, it may be the perfect fit for your volunteer activity. For additional information, go to our web site.


Managing Hungry Grasshoppers

Grasshoppers are showing up in masses in many parts of Oklahoma this summer. These insects like gardens because they have optimal moisture and excellent plant growing conditions that provide an abundant food supply.


People become alarmed when grasshoppers suddenly appear and begin feeding on prized flowers, vegetables, and ornamental plants. The distress can turn to frustration when grasshoppers are still seen after plants have been sprayed. In most situations, the spray worked and killed the grasshoppers that were there, but there is simply more grasshoppers moving in to take their place.


The insecticides available for grasshopper control have a limited residual activity and will not kill new arrivals after several days. Insecticides start to break down when exposed to sunlight, and the breakdown process speeds up as temperatures increase. In fact, in the summer when temperatures are high and sunlight intense, most insecticides will only work for about 24 hours. As summer progresses, grasshoppers get bigger, move faster and feed more intensely. All of this means that sprays will need to be repeated to keep plants protected with an insecticide late in the growing season.


Grasshopper management in the garden and landscape requires patience, and when possible, cooperation with your neighbors. The following suggestions are offered for managing grasshoppers:

  • Monitor Pests: Find hatching sites and spot treat them with registered insecticides. Best control is achieved if applied to immature grasshoppers (less than 1/2 inch long).
  • Protect: Use floating row covers to protect vegetables and prized plants. If the plants being protected require pollination (such as cucurbits), they may have to be hand-pollinated. Floating row covers are available at most garden and nursery supply stores.
  • Border Treatments: Irrigated yards and gardens are an "oasis" for grasshoppers during the heat of the dry summer months. The best way to control grasshoppers in this situation is to prevent them from ever entering the yard. Generally, grasshoppers move across areas in 'jumps' as they search for suitable food. You can slow or block their movement by treating all vegetation in a band or border perimeter around the yard and/or garden with an insecticide. Border treatments that are wider provide more effective control.
  • Biological Control: Several botanical and biological products are sold to manage grasshoppers. Nosema locustae is a protozoan microbe that causes disease in grasshoppers. Its resting spores are mixed into a bait which is then spread in areas with grasshoppers. The grasshoppers eat the bait and microbe spores, which then infect and kill the grasshoppers. Beauveria bassiana is another microbe (fungus) disease that can kill grasshoppers if sprayed on plants and they eat the spores. The fungus then infects and kills the insects. However, at best, these will provide moderate control and and may provide little to no control during hot and dry summer conditions.

For more information, see the OSU Fact Sheet  Grasshopper Control in Gardens and Landscapes.


Water, Precious Water       

If our last few years of drought have taught us anything, it is how valuable water can be when there isn't any. While we can't make mother nature turn on the water works whenever we need it, we are not completely helpless to manage the water sent our way when rain clouds appear. One option to help extend rainfall toward the improvement of our gardens is to build a rain barrel to harvest water runoff. Installing a rain barrel under a downspout can turn your roof into our own private rainwater collection system.

This is a relatively simple idea and can be done with little expense, depending on your level of skill. Deciding on where to place your rain barrel can be as easy as observing where you have space, where the water will be used and what downspout from your gutters will work best. After that, an easy option is to buy a rain barrel kit, which comes with everything you need to create a functioning rain barrel. Or, if you are feeling more adventurous, our web site has instructions on how to build an inexpensive one yourself.


While even the largest rain barrel would be empty during a drought such as the one we're currently experiencing, it will help reduce your overall water costs throughout the year.

Drought Rages On       

This is looking all too familiar...blistering heat and lack of meaningful rain for weeks on end. True, the drought took some time off early this spring in northeast Oklahoma, but has come back with a vengeance that harkens all the way back to...2011!


Severe to extreme drought conditions are once again gripping the area as we move into August. Technically, we are ever-so-slightly better off than we were one year ago, but the cumulative effect of back-to-back drought years is really taking a toll. In fact, going back to October, 2010, the Tulsa area has racked up a precipitation deficit of about 21 inches! That is becoming reminiscent of the 1930's "Dust Bowl" era.


August, if course, is typically a hot and dry odds are VERY high that this drought will get worse before it gets better. But, the one bit of good news that I can offer here is in the form of a developing El Niņo, which does tilt the odds in favor of above normal winter precipitation. Unfortunately, the effects don't typically carry into spring and summer...but, it's a start!


Up-to-the-minute weather postings are available at Oklahoma's Mesonet, or visit the National Weather Service Tulsa office online or on Facebook.

QandA  Q&A

Question: I am interested in growing some vegetables for the fall. What can I plant now and how should I do it?

Answer: Many gardeners think fall vegetables are the tastiest of the season. Several types may be planted now, either as seeds or transplants, but there are challenges related to the heat.


Fall vegetables fall into two categories-those sensitive to cold and ones more tolerant. Our average first frost is on November 3. The first hard freeze is 2-3 weeks later. Success depends on learning about each veggie you wish to grow. The OSU fact sheet suggests the dates to plant each veggie based on these average frost times. It will also inform you as to whether it is better to plant seeds or transplants. Transplants are usually hard to find in summer; you may wish to grow your own.


Veggies to be planted now include pole beans, sweet corn, eggplant, peppers, pumpkin, squash, carrots, broccoli and Brussels sprouts. Now is the time also to put new tomato plants in the garden for replacement or for a new bed. Tomato plants are now more widely available in summer than in years past, a testament to the interest in fall gardening.


Some veggies to plant later in August are green peas, lima beans, beets, cabbage, collards, cucumbers, Irish potatoes, leaf lettuce, radishes and turnips. Some cold hardy veggies which may be planted even later-garlic, leeks, onions and kale do well planted in September.


Most vegetable seeds will not germinate unless the temperature is less than 85°. It is currently 103°, 2" under bare soil, 87° under vegetation. To reduce the temperature, one can "pre-cool" the soil with mulch for a few days then pull the mulch back and plant in furrows a bit deeper than usual. Use mulch or a cloth shade after planting. You must also irrigate either by hand or use drip irrigation to maintain constant moisture.


Fall vegetable gardening is becoming more popular with our hot summers. Success is achievable but requires some planning. Obtain the OSU fact sheet to use as a guide. This covers what veggies to plant, how to plant them and time from planting to harvest. Tips are given on how to cope with the heat, using mulch, row covers and other types of shade.


Click here to send your question to the Tulsa Master Gardeners or see Answers to other Questions on the Web site