February 2014 / Volume 83             

In This Issue
Master Gardeners Spring Plant Sale
Winterkill in Bermuda
Rainfall Update
Making Potting Soil
Ask A Master Gardener...Growing Under Lights

Weather Stats for Gardeners

Soil Temperature 2" below sod:   

38 degrees 


Rainfall total last 30 days:  

0.26 inches


4 Ways to Contact Us
Email us at:

See our website at: www.tulsamastergardeners.org 

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.
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.

Tulsa County Master Gardeners
Spring Plant Sale
When? Thursday, April 17th, from 9:00 am to 7:00 pm
Where? Tulsa County Fairgrounds, Central Park Hall, Gate 12

If spring is not in the air, it is at least in our thoughts. In freezing temperatures, snow and ice, we have selected plants for our spring sale...the brightest annuals, the hardiest perennials, the best container accents and our favorite tomatoes! Start now planning summer flower beds, pots on the porch and replenished herbal gardens. Go to our website and review the great selection of plants we are offering. You will find pictures and descriptions of each plant.

Your plants will be available for pick-up on Thursday, April 17. Master Gardeners will be on site to answer your questions, make suggestions and provide information to make your spring planting enjoyable and successful.

Plants may be purchased two ways:
  • Preorder - NOW is the time to order great bedding plants, hanging baskets, herbs, tomatoes, ornamental grasses and accent plants. Order and pay online until midnight, Friday, March 28. There is also a PDF version of the order form online which can be printed, filled out and delivered (by mail or in person) to the Tulsa County Master Gardener office (4116 East 15th St, Tulsa, OK 74112-6198) by 4:00 pm, Friday, March 28th.  Master Gardeners will be available at the Extension Center on that day to accept your order with payment of cash, check or credit card from 10:00 am to 4:00 pm.
  • Plant Sale on April 17 - In addition to picking up any pre-ordered plants, you will find a wide variety of plants especially selected just for this one day sale, including natives, proven winners and other hard to find plants. These plants are sold on a first-come, first-serve basis. Didn't pre-order? No problem. The sale is open to everyone on April 17 from 9:00 am to 7:00am. SHOP EARLY, DON'T MISS THIS!
Proceeds from the Spring Plant Sale support the many Tulsa County Master Gardener programs that are provided free in our community. Thank you for supporting the Tulsa County Master Gardener Program!

Winter Injury in Bermudagrass    
Temperatures this winter have dropped to levels not seen in a few years...as cold as -2 in Tulsa, in fact. Due to these cold temperatures, some areas have experienced more winter-kill of bermudagrasses than in most previous years. Winter-kill is a relative term, meaning that some portion of a plant or portion of a turfgrass stand has died during the winter. Plant tissue death can be caused by dehydration, true low temperature injury, or a combination of the two.

Cold temperatures can damage warm-season grasses, such as bermudagrass, through a series of days and nights with sustained below freezing temperatures, or a series of unseasonably warm days followed by a sudden extreme drop in temperature to well below freezing. The grasses are especially vulnerable if they are types with poor winter tolerance and they are left unprotected by snow cover, and when soil temperatures are also below freezing. The amount of damage present on any bermudagrass stand varies greatly from year to year due to differences in weather and how it has been managed.

On rare occasions, winter-kill can be severe, such as when an entire turfgrass stand dies and no plant parts survive to regenerate the stand in spring. However, during most Oklahoma winters, only small portions of the upper aerial shoots system are killed. In this case, most crowns survive, leading to rapid greenup and turfgrass stand regeneration in the warm days of mid to late spring. Winter is not yet over, so we cannot project with great certainty the amount of winter-kill that will be detected once spring greenup arrives. However, it is not too early to begin scouting for winter-kill to assess the damage that has already occurred thus far.

When air temperatures have fallen into the low teens or several days have elapsed when air temperatures remained below freezing, scouting for winter-kill of bermudagrass should occur. Allow 7 to 10 days to elapse following a severe winter event to assess its effect on the bermudagrass stand. Several techniques are available for the homeowner or professional to use to gain insights into whether moderate to severe winter-kill of a bermudagrass stand has occurred.
Some comprehensive information on how to asses potential winter-kill can be found here.

It is also best to scout for winter-kill prior to application of the summer annual pre-emergent program. Most pre-emergent herbicides inhibit root formation on stolons to some degree and thus slow recovery of a stand that is being grown-in after severe winter-kill. Thus, if substantial winter-kill of bermudagrass has occurred, an informed decision as to whether to use normal use rates, reduced use rates or even forego application of the normal first application of the pre-emergent herbicide must be made. If substantial amounts of winter-kill have occurred such that the stand is not filling in quickly in spring see Fact Sheet HLA-6419 - Establishing a Lawn in Oklahoma).

Rainfall Update     
On the heels of a better growing season in terms of rainfall in 2013, as we start the new year wandering back into an old, familiar, and not too welcome situation. January has been very dry in the Tulsa area...the 4th driest on record in fact. The rainfall deficit actually goes back a while, as the past 90 days across northeast Oklahoma have seen no better than 50 percent of normal precipitation in most locations.

At the moment, the Tulsa area is still not technically in a drought, but is classified as being "abnormally dry". The official long range outlooks for precipitation this spring do not indicate favorable odds one way or another. So, in the meantime, be mindful of keeping your landscape watered even during the winter, especially evergreen plants. And, it might not hurt to try a rain dance!

Keep track of soil temperature and moisture locally on the Mesonet. View both national and local drought maps at US Drought Monitor here.

Making the Perfect Potting Soil         
Commercial potting soil mixes are widely available, but it is often difficult to identify what products they contain, including fertilizers. You can easily make your own potting soil, containing known ingredients, tailored for your own use.

An ideal potting soil should be able to hold water and nutrients but at the same time drain well. It should have lots of air spaces, not compact easily and contain no disease. The pH (acidity) level should be favorable for the intended plant use.

Most commercial potting soils are "artificial" and contain no actual garden soil but are mixtures of organic and non-organic materials. Garden soil alone will not perform well in containers - it is too heavy, drains poorly and may contain diseases. However, if sterilized, it has a use as one of the ingredients in some types of potting soils.

The most common organic products used for generic potting soil mixtures are sphagnum peat moss and ground pine bark, although many other types of organic composts are used. Vermiculite, perlite and sand are the usual non-organic components found in potting soils.

Peat moss is in most mixtures. Once wetted, it holds water very well and prevents drying. It is long lasting but has an acidic reaction and, in some cases, lime will be needed to adjust the acidity.

Ground pine bark is a useful potting soil ingredient, and is even better if composted. It performs similarly to peat moss but doesn't hold as much water. It has some fertility, aids drainage and may prevent some diseases.

Perlite and Vermiculite are products manufactured by heating minerals. This causes expansion much like popcorn. Vermiculite is made from the mineral mica and perlite from volcanic rock. Both are lightweight and will hold large amounts of air and improve drainage. Vermiculite will also hold water and nutrients. Sand, another useful nonorganic, also improves drainage and is often added to increase weight of potting soil for larger plants.

OSU's free fact sheet HLA-6411 - Housplant Care, has a recipe for a general potting soil mix. It is made of 50 percent peat moss, 35 percent ground pine bark and 15 percent perlite. This is but one of many recipes for potting soil. If fact, there may be as many recipes for potting soils as there are for homemade chili.

Question: What type of lights are the best to use indoors for growing plants?
Answer: Sunlight is composed of several different colors that are easily seen by looking at a rainbow after a rainstorm or light shone through a prism. Plants can make use of most of these colors, but it is the red and blue parts that plants depend on most for survival. In general, red light is needed for flower initiation, while blue light provides energy for photosynthesis (manufacture of plant energy).

Artificial lights vary a lot as to the colors they contain. Incandescent light, the standard old light bulb, has mostly red-containing light, while the widely used "cool white" fluorescent light has more blue light waves.

Sylvania, GE and others manufacture lights advertised as "grow lights" for use by the homeowner. Most are fluorescent lights but they are constructed in a way to either emit mostly blue or red lights or a combination of the two colors. The different bulb types fit the needs of a variety of plant growth requirements.

For most houseplants or for growing sprouts of vegetable or ornamental plants, it is best to use either fluorescent bulbs that emit both red and blue light or use a mix of bulbs, half red-emitters and half blue ones.

Incandescent lights may be used, but are not the best choice. Their life span is only a fraction of fluorescents and they generate heat that may injure plants. Also the electrical cost for an equal amount of light is much higher for incandescent than it is fluorescents.

Fluorescent grow lights should be placed about 6-8 inches above the plants and should be cycled on and off. A period of darkness is important for most plants. This gives the plant a break from energy production and allows it time to breathe. Indoor foliage plants do well with about 10-12 hours of light per day; flowering plants need 14-16 hours and seedlings should receive light for 16 hours per day.

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