February 2015 / Volume 95        

In This Issue

Weather Stats for Gardeners

Soil Temperature 2" below sod:   

43 degrees 


Rainfall total last 30 days:  

0.50 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

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.

February Lawn & Garden Tips
  • Base any plant fertilization on a soil test. For directions, see the left column or contact the County Extension Office.
  • Cool-season vegetable transplants can still be started for late spring garden planting.
  • By February 15 many cool-season vegetables like cabbage, carrots, lettuce, peas and potatoes can be planted. (HLA-6004)
  • Clean up birdhouses before spring tenants arrive during the middle of this month.
  • Avoid salting sidewalks for damage can occur to plant material. Use alternative commercial products, sand or kitty litter for traction.
  • Spray peaches and nectarines with a fungicide for prevention of peach leaf curl before bud swell. (EPP-7319)
  • Mid-February is a good time to begin pruning and fertilizing trees and small fruits.
  • Collect and store graftwood for grafting pecans later this spring.
  • Begin planting blackberries, raspberries, strawberries, grapes, asparagus and other perennial garden crops later this month.
  • Choose fruit varieties that have a proven track record for Oklahoma's conditions. Fact Sheet HLA-6222 has a recommended list.
  • A product containing glyphosate plus a broadleaf herbicide can be used on dormant bermuda in January or February when temperatures are above 50�F for winter weed control.
  • Fertilize trees, including fruit and nut trees and shrubs, annually. (HLA-6412)
  • Most bare-rooted trees and shrubs should be planted in February or March. (HLA-6414)
  • Finish pruning shade trees, summer flowering shrubs and hedges. Spring blooming shrubs such as forsythia may be pruned immediately after flowering. Do not top trees or prune just for the sake of pruning. (HLA-6409)
  • Look for arborvitae aphids on many evergreen shrubs during the warmer days of early spring.
  • Gall-producing insects on oaks, pecans, hackberries, etc. need to be sprayed prior to bud break of foliage.
    Dormant oil can still be applied to control mites, galls, overwintering aphids, etc. (EPP-7306).
  • Force spring flowering branches like forsythia, quince, peach, apple, and weigela for early bloom indoors.
  • Forced spring bulbs should begin to bloom indoors. Many need 10-12 weeks of cold, dark conditions prior to blooming.
  • Feed tulips in early February.
  • Wait to prune roses in March.

Time for Early Season Veggies!      
Gardening is a year round endeavor. We are barely a month into the winter season and it is already time to start our cool/early season vegetable garden. Since the weather in Oklahoma is prone to drastic changes, it is vitally important to monitor weather forecasts so steps can be taken to protect the fruits of our labor because even cool season plants have their limits.
The cold hardiest of the cool season vegetables are: asparagus, broccoli, cabbage, onions, green peas, radish, rhubarb, spinach, and turnip. Asparagus and rhubarb are best grown from crowns and will bless you with their scrumptious bounty year after year as long as you tend to their hydration and nutrition needs. With the exception of onions, the rest can be seeded indoors for planting dates ranging from mid-February through the first week in March.

Pay close attention to the maturation rates of broccoli because it tends to bolt (develop seeds) quickly. Also, cabbage will go to seed when temps are consistently below 40 degrees. Onions are best grown from sets and given the still short days of winter, the short day varieties will yield the best results. Spinach and radishes can be seeded in succession for a longer harvest period.

Beets, carrots, cauliflower, leaf lettuce, and potatoes are considered semi-hardy but can still be planted in late February to early March. All of these, except potatoes, are grown from seed, though lettuce and cauliflower will do fine if started indoors. Beets, carrots, and lettuce crops can be increased through succession seeding. Use the carrot seedlings as baby carrots when you thin them. You could also try mixing your carrot and radish seeds. The radishes will be ready before the carrots and will decrease the need for thinning the seedlings of both crops.

A fun technique to try if you have limited space is interplanting.  Slow start, late-maturing plants are planted between or within the rows of early spring veggies. When utilizing this technique, be mindful of sun/shade requirements as well as the nutrient requirements. This technique can also assist with pest control.

Regardless of the little tricks or techniques you employ in your garden, always keep in mind that as our temps reach 80 degrees or higher, our cool season veggies will tend to turn bitter or bolt. They thrive best when daytime temperatures are between 65 and 80 degrees, with average nighttime temperatures above 40 degrees.

So, get your garden ready, and start dreaming of the harvest!

Proper Soil Testing  
Did you know your soil needs certain nutrients to grow properly? Did you know that too much of any nutrient is almost as bad as too little? Did you know the soil pH needs to be within a certain range in order for nutrients to be properly absorbed by plants and grass?

As it turns out, all plants need 16 nutrients for optimal growth, and most are already in your soil. Nitrogen (N), Phosphorus (P), and Potassium (K) are the three main nutrients that are needed in the greater quantities.  

The best way to know what your soil needs is to have it tested. Soil tests provide a scientific basis for evaluating the available plant nutrients in homeowner's lawns and gardens. Properly managing the amount of nutrients that is added to the soil can save money and protect the environment. OSU's basic soil test measures the pH (the degree of alkalinity or acidity) and the three core nutrients mentioned above. Samples can be taken to the Tulsa OSU Extension Center which are then sent to the soil lab at OSU for analysis. The cost is $10 and generally takes two to three weeks to receive the results of the tests.

To ensure you receive an accurate analysis, be sure to correctly obtain your soil sample. Obtain 10-15 random sub-samples with a trowel or similar tool from the top 6 inches of the area you want tested.  Fewer samples will result in reduced accuracy. Perform separate tests on different areas; for example one for the lawn and another for the vegetable garden. Place the sub-samples from the particular area in a plastic bucket, mix thoroughly by hand, and submit about a pint of this mixture in a clear zip-lock bag to the OSU Extension Office. Soil samples should be fairly dry and clean of rocks and sticks. Do not sample an area which has received fertilizer within the past two months as this will give a false reading.

Generally, tests will indicate little to no phosphorus or potassium deficiency. In fact, most tests around the Tulsa area actually show a large excess of these nutrients.  There are two main reasons for this.  First, many fertilizers have both of these nutrients in addition to nitrogen. So, they get added right along with the nitrogen. Secondly, nitrogen is the only nutrient of the three that readily permeates through the ground. The others bind themselves tightly in the soil and are very slow to permeate. As as result, they tend to build up over time. Thus, soil tests are important not only for knowing what to add, but what not to add.

Once you receive results, use only the nutrients needed. Assistance in deciding the best soil amendments, based on soil test results, can be found in the OSU fact sheet titled "Improving Garden Soil Fertility". The best time to conduct soil testing is in the fall or early winter so there is plenty of time to correct for any nutrient deficiencies, based on the test results, before spring arrives and the growing season begins.

Personal Donations Help Keep the
Tulsa Master Gardener Program Going
Did you know The Tulsa Master Gardener Foundation actually receives no city, state or federal funding to run its programs? Most of the Tulsa Master Gardener programs are, in fact, self-funded. Income received from membership dues is actually less than 5% of total annual expenses. Tulsa Master Gardener's own fundraisers, such as the annual plant sale, garden tour and "garage sales" that occur from time to time. However, one other income source that sometimes gets overlooked are personal the donations (over and above the annual dues) that are made by our own Tulsa Master Gardener members. 

We think it is time to provide a little recognition to those folks that take the time, effort and sacrifice to make a monetary donation. Here is our first list of donors (from 2014 and so far in 2015):
  • Sandie Bailey
  • Deby Frost
  • Judi Hofer
  • Steve Jaynes
  • Janie Joswick
  • Lee Kutner
  • Steve McCurley
  • Dianne Nail
  • Larry Rogers
  • LaDonna Van Horn
  • Judy Ward
  • Rebecca Whisenhunt  
Other honorable mentions include two people from outside our program:
  • Gary Stanislawski, CFP, Regent Financial Services, Tulsa
  • Dale Nicola, Tulsa Cleaning Systems - donated a Dramm WC20 Watering Cart (in memory of Lynn Bulla, a former Tulsa Master Gardener)
A big THANK YOU goes out to these folks for helping the Tulsa Master Gardener Program. Each month that one or more donations are received, recognition in this newsletter will be made. So, keep an eye out if you make a donation.

Question: When should I plant onions and potatoes?

Onions and potatoes are just two of several cool season vegetables which are suggested to be planted between February 15 and March 10 in an average year.

Onions come in two forms. They may either be planted as small bulbs (sets) or as small plants in a prepared garden bed.

Irish potatoes, but not sweet potatoes, should be planted as cut potato pieces. These should each be about 2 ounces in size and are best obtained from certified seed potatoes.

Before planting, spade or till the garden beds and it is always a good idea to add some organic compost, such as rotted cow manure.
Other vegetables which may be planted during this time frame are cabbage, carrots, cauliflower, Swiss chard, head and leaf lettuce, green peas, spinach and turnips.

OSU has a wealth of free fact sheets to get vegetable gardeners started. These fact sheets are available online at tulsamastergardeners.org or from the OSU Extension office at 4116 E. 15th street (gate # 6 into the fairgrounds).

Consider obtaining these fact sheets:  F-6004, "Oklahoma Garden Planning Guide", F-6032 "Vegetable Varieties for the Homeowner", F-6020 "Growing Vegetable Transplants" and F-6012 "Growing Tomatoes in the Home garden".

Question: I am preparing to put out onion sets. I have heard that adding sulfur will improve flavor.

Answer: Mid-February to mid-March is the time to plant onions using sets (small bulbs) or transplants. There are many varieties. Oklahoma State University fact sheet No. 6032, "Vegetable Varieties for the Home Garden in Oklahoma," lists types which do well in Oklahoma. Onions are classified several ways. They are grouped by color: yellow, white and purple and they are divided by whether or not they form bulbs. The ones without bulbs produce scallions, or green onions. The bulb-forming onions are further divided into the length of days needed for bulb formation. Long-day varieties are grown in the northern United States; the short- or intermediate-length types do best in Oklahoma. Onions are also classified as to hotness or pungency, which gets into the use of the plant nutrient sulfur. The degree of hotness is related to several sulfur-containing chemicals. Sweet onions such as Vidalia or Texas 1015 are naturally low in sulfur compounds, and mildness is enhanced by growing in low sulfur sandy soil. Hot onions have high levels of these chemicals. Studies done at Cornell University conclude that there are probable health benefits from these and several other chemicals found in onions. Experiments have shown adding sulfur increases the pungent chemicals two- to threefold in some onions. The problem is that there are no guidelines as to how much sulfur to add or which types of onions respond best. When too much sulfur is added to the soil, it causes excessive acidity which can be harmful to plants. We cannot recommend adding sulfur. For now, onion lovers should be aware that mild Vidalia-like onions taste best, but the tear-producing hot varieties may be more healthful.


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