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April 2011                                                                 Number 48  


"April is a promise that May is bound to keep."  ~Hal Borland


Soil temperature, 4" below sod: 53 degrees                             Rainfall total, last 30 days: 0.72   


 Ask a Master Gardener


Question: I am finally going to attempt to plant azaleas! What are the important things to know?  


Answer: Planting an azalea is not difficult. The first step is choosing the right spot. A bright spot with an eastern or northern exposure with morning sun only is best. Azaleas thrive in acidic, well-drained soils. You can bring in a soil sample to find the pH of your soils. Dig the holes, or an area for multiple azaleas, wider than the root ball(s) but not deep. Place azaleas close enough together so that branches are touching each other. Amend the soil with a mix of one part pine bark mulch (don't use pine bark nuggets) and one part cotton burr compost. The pine bark mulch will deter Verticillium wilt caused by soil-borne fungi, while the cotton burr compost will feed the roots and promote good drainage.

Plant with the root ball 1-1� inches above ground level to allow good drainage, then mulch with more of the pine bark mulch and cotton burr compost mix. Water well and wait to prune after all blooms are spent. Fertilize plants in fall with an acidic fertilizer for azaleas. Click here for more azalea tips visit. For more about soil tests click here


Question: My vegetable garden is shaded by large trees for most of the afternoon. I still want to plant tomatoes and peppers. What can I do?


Answer: Sun-loving vegetables require four to six hours of direct sunlight to thrive. One option is to plant veggies in large enough pots to retain moisture during the hot summer months, yet light enough to be moved about the landscape or patio as the sun exposure changes. It is important to supplement with fertilizer and water in pots and stake as needed. Another idea is to plant vegetables and herbs in the perennial garden or among ornamentals. This new trend is the same idea behind the cottage gardens that contained both flowering and edible plants. Combine plants with similar needs for sun exposure and water.


Question: Should I prune young trees with more than one leader?

Answer: It is important to train and prune trees while they are young to prevent breakage from wind or ice load. The leader is the central branch that grows vertically in the center of most trees and is part of the scaffolding or general shape of the tree. This is not true of every tree, as some trees have numerous limbs that form the canopy, such as the Lacebark Elm. Often trees with two competing leaders, or co-dominant branches, will have a V-shaped space or crotch between the two limbs. This is compared to a U-shaped crotch that does not usually have what is called "included bark," or plant material connecting both branches in a way that does not provide strength. Studies have found that V-shaped crotches (with included bark) are significantly weaker than U-shaped crotches for all species. Prune the limb that forms the weakened V-shaped crotch from young trees.

If in doubt, bring a picture of the co-dominant branches into the OSU Extension Center on Monday thru Friday from 9 a.m. to 4 p.m. and let the Master Gardeners help.


Question: I have heard about "sustainable" gardening and am not sure I understand it, or how it affects our environment and being more "green."


Answer: Sustainable gardening generally refers to practices that can be continued with minimal long-term effect on the environment. In other words, we do not use chemicals or cultural practices that might affect the future of our area or the planet in adverse ways. Sustainable gardening also intimates what OSU calls "Earth-Kind" gardening. It includes such ideas as composting, utilizing rain barrels, mulching, restricting the use of pesticides, introducing beneficial insects, planting native plants and encouraging pollination by bees and butterflies by providing nectar and host plants for caterpillars. In the context of "Going Green," it implies the need for reducing consumption and reusing or recycling products, steps that will help preserve the planet for future generations. One of our

Tuesday evening free classes 

will discuss this topic in detail. 


4 Ways to Contact Us


See our website at: 

Call: 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.

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14 lawn and garden tips for April  



  • April 15 is usually a safe date to start planting bedding plants and annual seeds.
  • Plant summer-flowering bulbs such as dahlias, cannas and elephant ears when soil temperature has warmed to 60 degrees. Caladium bulbs need warmer soil, up to 70 degrees. The soil temperature at the Bixby station is shown above.
  • You can fertilize roses now, using a recommended rose formula fertilizer.
  • Mulch trees and shrubs now. Recent research shows that newly planted trees that are mulched grow up to three times faster in their early years. However, wait until soil warms before mulching garden beds.
  • Prune winter-damaged limbs and plants. Prune spring-flowering plants like azaleas and forsythia after blooming. Click here for Fact Sheet 6409, "Pruning Ornamental Trees, Shrubs and Vines."  
  • Let the foliage of spring-flowering bulb (daffodil, tulip, etc) remain as long as possible before cutting it back.
  • Ruby-throated hummingbirds arrive from Central and South American this month. Put out sugar water using one part sugar to four parts water. A red dye is not needed.
  • Clean out water gardens; divide and repot plants. Begin feeding fish when the water temperature is over 50 degrees.


  • Warm-season grass lawns can be established from sod or sprigs, beginning in late April. Click here for Fact Sheet 6419, "Establishing a Lawn in Oklahoma."  
  • This is the second-best time to over seed your fescue lawn. (Last fall would have been the best time.) Don't over seed if you have applied preemergent herbicide this year.
  • Tall fescue should be mowed 2.5" to 3" now through fall.
  • Mow Bermuda lawns to 1" to 1.5" at first, then 2.5" until fall, removing no more than a third of the grass height each mowing.
  • Fertilize Bermuda lawns only after fully green, which is usually late April. Bermuda needs 3 to 5 pounds of nitrogen per 1000 sq feet yearly, in divided applications, April thru August. Click here for Fact Sheet 6420, Lawn Management in Oklahoma.  
  • If you didn't fertilize your cool season lawn (fescue and bluegrass) in March, do so in April. Don't fertilize again until September and November.
Free Gardening Classes

Our popular gardening classes are held at 5:30 p.m. every Tuesday in April and May at the OSU County Extension Offices, 4116 E. 15 Street (gate 6 at the fairgrounds). Each class lasts 30 minutes, but we will stay to answer any questions. There is no cost and no pre-registration; just stop on your way home from work and learn.

  • April 5- Miniature Fruit Trees: Learn how to choose the right root stock and grow fruit trees in small spaces. Also up for discussion will be fruit tree espalier and some of the cultivars available.
  • April 12-Raising Chickens in your own Backyard: Discover what is lawful to do in the city limits of Tulsa and surrounding towns, plus the how-to of small yard chicken care and breeds available.
  • April 19-Tomatoes in Small Spaces: Join a discussion of all vegetables and herbs that can be successfully grown in containers and small gardens, along with the how-to details.
  • April 26-Bloomin' Containers: See a demonstration of successful  but unusual plant combinations, including perennials, annuals, tropicals and herbs. The "Tulsa Blooms!" project will be explained for homeowner's participation.

Check back next month for a list of four more presentations in May.


Plant sale pick-up reminder 

If you ordered plants from the Master Gardeners, remember that pick-up is from 9 a.m. to 7 p.m. Thursday, April 14, at Central Park Hall, Tulsa Fairgrounds. Use the 21st Street entrance.  


Even if you did not place an order, check out the additional plants that will be available separately on the day of sale. More herbs, hanging baskets, vegetables, ferns, perennials, native plants, Oklahoma Proven varieties and other plants will be available to purchase on a first-come, first-served basis.  Master Gardeners will be on hand to answer questions about the plants we offer. The annual Master Gardener plant sale provides about 80 percent ofthe funding for the many educational services and programs provided free of charge in Tulsa County.   

Become a Master Gardener

Learn. Plant. Share. 



demo front yard 

The Tulsa County Master Gardeners are OSU-trained volunteers who provide lawn and garden information and support to home gardeners and the community. The "Ask a Master Gardener" telephone help line, the elementary school programs, senior living programs and "Tulsa Blooms!," a county beautification project, are just a few of the projects sponsored by the group. Orientation sessions will be offered twice in August. There is no cost or obligation to attend. The two-hour sessions will explain the program, the classes and the volunteer opportunities. Classes begin in September. Click here to register for more information.


Need more information?

Click on any of the links below:

Become a Master Gardener


Back Issues  

Past issues of our eNewsletters can be read and download.

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.
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 100, by size and color.
Oklahoma Proven Plants
The new list for 2011.  State horticulturists, nurseries and growers pick their favorite plants, shrubs and trees.
Current and historical source of rainfall, air temperatures, soil temps and much more. Click on Bixby station.   
Classes start in September. Register for more information.
    tulsa county logo Extension Logo
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.