September 2014 / Volume 91       

In This Issue
September Lawn and Garden Tips
Order Fall Plants Before Sale Ends!
Fall Armyworms
Peony, Queen of Flowers
Fairy Rings
Ask A Master Gardener...Fescue re-seeding

Weather Stats for Gardeners

Soil Temperature 2" below sod:   

78 degrees 


Rainfall total last 30 days:  

2.14 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

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.
Cool Season Lawn Care (Fescue)
12-month maintenance calendar.
Warm-Season Lawn Care (Bermuda)
Ditto above.
Trees for Tulsa
A list of recommended trees with descriptions.
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 each year. Register at our office on 15th Street 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.

September Lawn and Garden Tips     
  • You have all of September to plant cool-season vegetables like spinach, leaf lettuce, mustard and radishes, and until the middle of September to plant rutabagas, Swiss chard, garlic and turnips. Click here for Fall Gardening Guide.
  • Last nitrogen fertilizer application of the year on warm-season grasses should be applied no later than September 15. (HLA-6420)
  • Winter broadleaf weeds like dandelion will begin to emerge in late September, which is also the best time to control them with a 2, 4-D type herbicide.
  • If pre-emergent control of winter-annual weeds (henbit, chickweed, annual bluegrass, etc.) is desired in lawns, the application should be completed by the second week of September. Note: Do not treat areas that will be seeded in the fall.
  • Continue bermudagrass spray program with glyphosate products for areas being converted over to tall fescue this fall.
  • Plan to seed bluegrass, fescue or ryegrass as needed in shady areas in mid- to late-September. Fall is the best time to establish cool-season lawns (HLA-6419).
  • White grub damage can become visible this month. Apply appropriate soil insecticide if white grubs are a problem (EPP-7306). Water product into soil.
  • Watch for fall specials at garden centers and nurseries since fall is a great time for planting many ornamentals.
  • Choose spring flowering bulbs as soon as available.
  • Plant cool-season annuals like pansies, ornamental cabbage or kale, snapdragons and dusty miller when temperatures begin to cool.
  • Watch for and control any late infestations of tree webworms.
  • Twig girdler insects should be controlled if large numbers of small branches of elms, pecans or persimmons are uniformly girdled from the tree and fall to the ground.
  • Begin to reduce the amount of light on outside tropical houseplants by placing them under shade trees before bringing them indoors for the winter.

Order Fall Plants Before Sale Ends!   
We are pleased to offer our pansies and panolas again this year for your fall garden. Our selection of colors has been increased and is available for viewing on our website. These winter hardy plants will give you color from October through May.The deadline for ordering is Friday, September 19. The plants are sold in flats of 36 (6 six-packs) for $16. As always, sales tax is included in our price.The plants will be delivered fresh from our grower on Wednesday, October 8.  You can pick up your flowers on that day from 10:00 am to 3:00 pm at the OSU Extension Center, 4116 E. 15, Gate 6.  We look forward to seeing you there. These plants are being offered through our online shopping cart only. You may click here to access the catalog and view the selection of plants we are offering 

Fall Armyworms Beginning
to Invade Turfgrass   
Eric Rebek, Extension Entomologist
Infestations of fall armyworms have been observed in bermudagrass in area pastures since mid to late July, and it seems subsequent moth flights are producing larvae that may be poised to invade lawns, golf courses, sod farms, and other landscapes. Fall armyworm populations reaching densities of 10 to 15 larvae per square foot have been observed in research plots of tall fescue at the OSU Botanical Gardens.

Fall armyworms are surface-dwelling "climbing cutworm" caterpillars. They prefer to eat grasses, and often go unnoticed until they become large and their feeding damage becomes evident. Fall armyworms tend to prefer tall fescue, but they also feed on bermudagrass and other turfgrass species. Larvae develop through 6 instars. One generation of fall armyworm can develop in about 18-28 days, depending on temperature, and infestations may occur until the first "killing frost". In Oklahoma, there are 2-3 generations present from late July through late October. Fall armyworm cannot overwinter in Oklahoma, hence its arrival later in the growing season.

Mature fall armyworms measure 1� inches long when fully grown. Their body color can range from green to brown or black, and they have a distinct stripe along each side of the body. Their head capsule has a prominent, inverted, white "Y" at the front. A magnifying glass or hand lens may be needed to see this characteristic on smaller larvae. Small larvae do not consume the entire leaf tissue but instead scrape off all green tissue, leaving a clear membrane that gives the leaf blade a "window pane" appearance. Larger larvae (4th through 6th instars) can chew through the entire leaf.

Feeding activity by flocks of birds can serve as a sign that armyworms are present. Fall armyworms can be detected through close examination of the turf, or by using a soapy water flush. A soapy water flush involves mixing 1 tablespoon of lemon-scented dish soap per gallon of water and pouring the solution over several small areas of damaged turf. If present, larvae should be visible within 30 to 60 seconds as they become irritated by the soapy water and leave their hiding places in the thatch.

Homeowners should carefully consider the need to control fall armyworms before taking action. Some cool-season turfgrass could recover from a fall armyworm infestation late in the year without treatment, and bermudagrass and zoysiagrass lawns may be only slightly damaged and not warrant treatment. However, early indications this year suggest chemical treatment will be needed in many areas, especially for protecting cool-season turfgrass.

There are many insecticides that are registered for control of fall armyworms that can provide excellent control. Note that products containing microbial active ingredients (i.e., Bt and spinosad) should be applied when caterpillars are small for maximum effectiveness. If choosing between granular and liquid applications, keep in mind that granular products are a bit slower acting, and require watering for activation. As always, read the insecticide label for important information about using the product safely and effectively.

Peony, Queen of Flowers    
Want a low maintenance, beautiful and reliable plant for your garden that returns every year?  Try some peonies in the back of a border. For spontaneity, exuberance and beauty, few perennials can surpass peonies. Each spring, this hardy perennial comes up from just a few roots to become a sturdy, shrub like plant with dense, leathery foliage and dozens of exquisite flowers. They are native to Asia, Southern Europe and our Pacific Northwest. Once planted, a peony may live for decades. Peonies make wonderful cut flowers in spring arrangements. They usually bloom about the same time as tall bearded iris.

When to plant: Peonies may be planted in the fall any time before the ground freezes. Spring planting is not recommended because the plants begin their top-growth before the roots have become well established.

Where to plant: Select sunny and well drained location where they will receive at least a half-day of sunshine. The best blooms usually are found on plants growing in full sun. Do not plant near large trees or heavy shrubs where they would be robbed of moisture and nutrients. Because of their large blossoms, peonies are at their best when grown in large groups to create a mass of color. After blooming, these dark green glossy plants provide a perfect backdrop for other shorter perennials and annuals. Mulching around plants will help in retaining vital moisture.

Disbudding: Most varieties of peonies develop several small side buds near the base of the terminal or end bud. If large flowers are desired, the side buds should be removed so that the plant's strength will all be directed to the terminal bud.

Staking: If the flower head is large and heavy, the stem may not be able to support its weight.  Watch closely in spring as green shoots emerge from the is much easier to properly locate the stake prior to the plant developing branches and leaves. Carefully place a hoop-type stake or wire support around the plant before too much growth emerges.  
What to expect: Do not be discouraged the first and second year after planting if the growth is low and slow to develop. It may or may not bloom during this time. Be patient, as it may take three years before the plant produces the expected blooms.

Why Peonies Do Not Bloom: The most common cause is that the root was planted too deeply. In our climate, the red eyes (sprouts) on the root should be placed no more than � to 1 inch below ground level for best flowering. Peonies do not transplant well when mature, so plant them in a spot where they will stay.

Fall Care: After the first heavy frost, trim away dead leaves and stems, cutting them down even with the ground. Do not put in compost pile as they may contain disease.

Fairy Rings: What are they and
what should I do about them?     
Fairy Rings sound like something out of a fairy tale, which might be interesting or entertaining to some, but not so much to you as a gardener if they are in your yard. Fairy rings are actually produced by many varieties of underground fungi. Fairy ring damage appears in a target pattern.  They typically expand from a central point into an arc or circle and are particularly noticeable when they grow in our lawns. The appearance is variable and may occur in essentially all types of lawn grasses. While they are most notably a ring of small, tan mushrooms, they may also appear as either green or brown rings. The grass in these rings or circles may be greener than any other grass in your lawn. They can range in size from a few inches to several hundred feet in diameter, and may persist for years.

Fairy rings typically occur from late spring to early fall and can disfigure a lawn. The fungus feeds on organic matter in the soil. Sometimes as it feeds, it frees up nutrient nitrogen in the organics, thus creating dark green rings in lawns. However, many times this organic matter is the result of a tree that died some time ago or old, buried wood that is simply decomposing. The decomposition feeds the fungus, thus creating the mushrooms. The fungus is especially problematic in acid soils. As the mushroom fungus multiplies, its white underground growth (mycelium) becomes so dense and tough that water cannot penetrate the lawn. Starved and thirsty as weather warms up, grass around the mushrooms may die. The resultant mushrooms or puffballs may appear overnight, particularly after a rain, and should be removed as soon as possible.    
So, what to do about it? Well, management of this is not easy. If possible, remove old tree roots and stumps or buried wood. Be sure to pick all mushrooms before caps open up and release spores. Apply lawn fertilizer containing nitrogen to revitalize fairy ring center and aerate soil during the growing season. Finally, ample deep watering can help to minimize the loss of grass due to the fungal dehydration, along with more frequent mowing. There are fungicides labeled for fairy ring control, but they usually require a certified professional for application. If grass is lost, reseeding may be necessary. The only real option for complete elimination of the fungus is to remove and replace both the soil and the grass.

Question: I have some areas of my fescue lawn which need re-seeding. What is the best variety of fescue to use, and when should I re-seed?

Answer: There is no one best fescue variety, according to the OSU turfgrass specialists, but there are some which perform better than others. OSU was involved in the evaluation of over 60 varieties of tall fescue a few years back and the results are published in OSU CR-6602 report, available online. OSU suggests using a blend of more than one fescue variety with or without Kentucky bluegrass seeds. A diversity of seeds will be more tolerant of extreme heat and disease pressures of summer. Some of the useful commercial brands with a blend of tall fescues, with or without Kentucky bluegrass, are 5 Star Fescue and Heartland Supreme. Fortunately, local merchants usually choose the more adapted varieties for the Tulsa area.

The ideal time to overseed cool season lawns is mid-September through mid-October. This will give it enough time to establish a good root season before the stress of the following summer.

Fortunately, much of this summer saw below normal temperatures and adequate rainfall - a good thing for fescue and bluegrass. Most of the loss of cool season grasses is directly related to high temperatures, humidity and lack of water. These conditions kill fescue outright or promote a disease called "Brown Patch". Unfavorable soil pH (acid level) and inadequate nutrients may also cause fescue loss, creating a need for yearly reseeding. To help sort the problems out, always perform a soil test before getting started.

Reseeding is more than tossing some seeds on bare spots. Weeds need to be removed and the soil prepared either by hand or by machine. The prepared bed should be smooth, without clods and the soil should be moist. A starter fertilizer, based on the results of a soil test can be incorporated when the soil is prepped or after seeding. Apply the seed at the recommended rate of the seed label, seeding in a crisscross pattern to insure good coverage.

After seeding, the bed absolutely has to be kept moist the first 3 weeks. This may require brief irrigation twice daily, depending on wind and temperature. Mow after the grass is 3 inches tall. If needed, a postemergent herbicide for broadleaf weeds may be used after the third mowing.

OSU has a fact sheet, "Establishing a Lawn in Oklahoma" which has details about reseeding established lawns or creating a new one with tall fescue..

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