January-February 2014 / Volume 82            

In This Issue
January-February Lawn and Garden Tips
Cleaning Up After Winter Storms
Trees for a Better Future
Easier Chores With Clean Sharp Tools
Mistletoe: Friend or Foe?
Ask A Master Gardener...Ice Melt Pros and Cons

Weather Stats for Gardeners

Soil Temperature 2" below sod:   

40 degrees 


Rainfall total last 30 days:  

1.93 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.
January/February Lawn and Garden Tips 


  • Sterilize pots and garden tools. Use one part household bleach to nine parts water. Soak for about 15 minutes, rise, and let dry.
  • Try to recycle your cut Christmas tree rather than sending it to the landfill. It may be used as a bird shelter, sunk into a pond for fish habitat, or cut or ground up for mulch or the compost pile. Tulsa also has a free green waste recycling center at 10401 E. 56th St. North, which will take your tree (and all other green waste) and will also give you free wood chip mulch, if desired. Southwood Nursery will take all Christmas trees and recycle them whether or not it was purchased there. No matter your tree's final destination, be sure to remove all ornaments.  
  • Obtain the fruit tree spray schedule from the Master Gardener office or web site.   
  • Horticultural oils and fungicides may be used this month for fruit trees. Each fruit type has a different schedule.  
  • Begin planting blackberries, strawberries, grapes and other perennial garden crops later in February.  
  • Cool-season vegetable transplants can still be started for late spring garden planting. Plant tomato seeds in indoor flats around Valentine's day for mid April garden transplants.  
  • By February 15 many cool-season vegetables like cabbage, carrots, lettuce, peas and potatoes can be planted.
  • Green winter weeds, such as henbit and dandelions, may be controlled in dormant (brown) Bermuda lawns with glyphosate, a herbicide found in Roundup and others. It cannot be used on fescue or zoysia lawns.
  • Mid-February is the time to apply a preemergent herbicide to prevent crabgrass in lawns. 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.


  • Keep all shrubs and perennials, especially evergreens, watered during dry conditions. Don't forget those under eaves and other protected areas. Watering deeply before predicted hard freeze will reduce chance of winter damage. 
  • Mulching all plants will conserve water and insulate the soil. 
  • Fertilize pansies and violas on a mild winter day. Water when soil is dry. 
  • If you have unplanted bulbs from the fall, plant them ASAP. They will bloom less reliably and will have shorter stems, but cannot be saved for the following year. 
  • All bare-rooted trees and shrubs (including roses) should be planted in February or March as weather permits. Plant what can realistically be maintained, watering when needed through the winter and mulch generously. 
  • Wait until spring to plant smaller shrubs, perennials and ground covers. 
  • Deciduous shrubs and trees can also be transplanted, weather permitting. 
  • The dreary weather of February is a good time to sit back and design your landscapes for spring. The Oklahoma Proven selections at www.oklahomaproven.org offer lots of ideas for trees, shrubs, perennials and annuals. 
  • All trees, including fruit and nut trees, along with shrubs and evergreens may be fertilized now. A soil test done at the County Extension office at 4116 E. 15 street will recommend what fertilizer nutrients to use. 
  • Finish pruning shade trees, summer flowering shrubs and hedges. Wait to prune roses until mid-March. Spring blooming shrubs such as forsythia and azalea may be pruned immediately after flowering. Don't prune crapemyrtles without a reason.
  • Cut back "monkey grass" (liriope) and all ornamental grasses, such as Pampas grass before new growth begins. 
  • Horticultural oil in dormant strengths can still be applied to trees to control mites, galls and overwintering aphids.  
  • Spring-flowering bulbs such as Daffodils should be fertilized as soon as they emerge in late winter. Tulips which are grown as annuals do not need fertilizer.  

Cleaning Up After Winter Storms   
The Tulsa area has once again been the victim of an ice storm. Thankfully, this storm was not as severe as the devastating one in December of 2007, which still has had a lingering effect six years later. Nonetheless, with any notable ice storm, there has been plenty of tree and other landscape damage to be dealt with, and the clean up will no doubt continue for a while.

Many of the trees damaged will be susceptible to disease and insect infestation over the next few years. The problem is there is no sure way to tell now whether a tree has potentially fatal damage. The predicament is whether to remove a damaged tree or repair it and see whether it survives. Of course, the time spent waiting on the outcome, which may be a few years, is time that could have been invested in growing a young tree.

First, you should deal with any tree that represents a threat to you and your property as soon as possible; and if you have no immediate threats, take your time. Next, consider the factors that affect tree survival. One is how much of the crown (the branches that make up the top of the tree) is damaged. The Oklahoma Forestry service categorizes the degree of damage and chance of trees surviving an ice storm according to the amount of crown loss. Less than 50 percent loss is considered "light damage" and trees have a high chance of survival. Those with more than 75 percent loss of the crown are thought to have a low chance of survival.

Other factors include the species, health and age of the trees before the storm. Older trees with disease fare worse than young healthy ones. Trees with damage to the main trunk, including splitting of the trunk and loss of bark, are much less likely to survive. Another important aspect of your assessment is the value of the tree to you personally and what it adds to your property value. Regarding shrubs -- you should prune out all of the injured stems now. Extensively damaged shrubs may end up with only a few healthy stems, but they should recover. However, it might take two to three years to get back to your starting point. Another choice for a shrub that has major damage would be to replace it in the spring. While going through this process, you might need some help. An arborist might need to be consulted for advice and trimming or removal services. If you consult an arborist, make sure he or she is a member of the International Society of Arboriculture (ISA) and is insured and bonded.

A list of certified arborists in Oklahoma is available from the Oklahoma Forestry Services' web site. This site also has general information concerning ice-storm damage. If you do not have access to a computer, a printed packet of this material is available at the OSU Extension Center, 4116 E. 15th St. Should you decide to keep your tree, an arborist can prune out the damage and even put in cables for support, if needed. It is important the broken stubs of limbs be removed carefully at the trunk of the tree and the damaged limbs pruned back to a healthy branch.

If you decide to prune the trees yourself, consider consulting OSU fact sheet No. 6409, from the Master Gardener web site, or the Forestry Service web site. Both sites outline pruning basics. Be aware that pruning trees is a dangerous business and many people are injured yearly from chain saws and falls from ladders and trees. After the tree has been repaired, it will need good care, including regular deep watering when dry and springtime fertilization. The main point is to take your time to make these decisions. There is no need to decide what to do now. Also remember that no tree is worth a serious personal injury, so keep yourself safe so you can enjoy your trees and shrubs in the future.

Trees for a Better Future   
If you are interested in planting a new tree for your landscape, you may be interested in which trees can survive our climate's extremes. Trees can generally be divided into groups based on their susceptibility to ice damage. Those more likely to be damaged are those with broad crowns and fine branching, which offer more surface area for ice to accumulate. Other undesirable features are lopsidedness, existing disease and weak attachments of the limbs to the trunk. An attachment with "included bark" causes structural weakness and is a feature of Bradford pear trees, causing them to be susceptible to ice and wind damage. Included bark is bark grown into the wood at the juncture of limb and trunk, much like an ingrown toenail. These structural features seem to be more important for ice storm susceptibility than the actual strength of the wood itself.

Another undesirable feature of some trees is leaf retention. The leaves offer more surface area for ice to accumulate. This is common in many oaks. A desirable tree in terms of ice damage, then, is one with a more cone-shaped crown structure, fewer and larger branches, strong attachments of branch to stem and a lower overall surface area. This desirable tree would also be one that has regular pruning to promote balance of structure and removal of limbs that are diseased or showing weakness at the juncture with the trunk. We are in an ice damage zone, as is the whole of the upper Midwest and northeastern part of the U.S., and tree selection based on tolerance of ice loading should be a consideration. However, this should not be the sole consideration. One should not forget to match the predicted size of the tree with the location.

The massive power outage we have experienced with ice storms in the past emphasizes the need to avoid planting tall trees under power lines. PSO has an excellent free booklet entitled "Tree Tips, A Planning Guide," available from PSO or at the Master Gardener's OSU Extension office, 4116 E. 15th St. This guide outlines power-line friendly trees. There have been several studies of trees for urban areas and their susceptibility to ice damage. Generally those most prone to damage are Bradford pears, common hackberry, some ashes, locusts, pin oak, some cherries, river birch, American linden, willows, elms and many pines.

The intermediate list includes bur oaks, white pine, northern red oak, red maple, sycamore and tulip tree. Those listed as most resistant are sweet gum, arborvitae, bald cypress, black walnut, catalpa, hemlock, ginko, Kentucky coffee tree, little leaf linden, swamp white oak, white oak and Norway maple. Not included in the study cited, but probably belonging in the resistant category are the Chinese Pistache and the Oklahoma redbud.

Other constraints to what you may wish to plant as a replacement tree in the spring will be what is available. Tulsa is fortunate to have some excellent nurseries and nurserymen. They generally have a good variety of stock and a wealth of informative recommendations about what and where to plant your new tree.

Easier Chores With Clean, Sharp Tools    
Winter is a great time to be indoors looking at gardening catalogs, right? Think about lightening your load of labor for spring and summer with some maintenance on your garden hand tools. If you have ever "fixed" the handle of your favorite hoe with electrical tape, then this is the time to take some action.  Spend some time in a treatment schedule of your preferred tools for more productive hours in a later season.

Clean the tools after each use. Doing so keeps from spreading disease, weed seeds, fungi, and insect eggs around your property. It also prolongs tool life. Any tools that come in contact with soil need to be rinsed off after each use. Turn the hose nozzle to high pressure to loosen soil. If you have clay soil, you may need to use a brush. Dry thoroughly with an old towel to help prevent rust.

Tools that don't contact soil should be wiped down with a thick cotton cloth to remove sap or gums collecting on sharpened edges, such as on axes, pruners and knives. If you are working with a tree or shrub that produces pitch, wipe the blade with a little paint thinner prior to use and the tool should clean up easier after use. Then thoroughly dry with your towel.

Oil application prevents rust. Tool heads made of steel tend to rust when exposed to air. To keep rusting to a minimum, motor oil applied to the steel is inexpensive insulation against rust. Try using 30W motor oil with one pint of kerosene or lamp oil in a 2:1 ratio. Wipe or spray on your metal tool head in a thin layer so it doesn't drip off the tool onto the floor. The oil will not adversely affect your soil. For light rusting, a chemical rust remover may help. If the tool is extremely rusty, you may have to use 80 grit sandpaper, a stiff wire brush or even an electric drill with a wire brush attachment. Safety glasses should be used for these methods.

Sharpen tools for peak efficiency. The most basic tool for sharpening is an 8 inch long mill file with a handle on the end. Work by drawing the cutting teeth in one direction over the blade edge. This works better if the tool is placed securely in a vise or clamp. For pruning shears and knives, a honing stone (whetstone or pumice stone) works better. Slide the blade in one direction over the flat surface of the stone until the desired sharpness is reached. Many manufacturers have a website with specific instructions for care of their tools, including lubrication of moving parts.

Storage Space for tools. Of course, there is never enough, but it helps if your tools are organized with a specific space for each tool. That makes it easier to see what's missing and remember where you left it.  Return tools to the same spot each time. Put them away when you are through with your task and don't leave them outside, even if no rain is predicted. Wet grass and dew can still damage them. If you are a bit forgetful, paint the wooden handles red so you can find them more easily.

For more productive time in the garden, keep your tools in shape by spending a bit of time this winter preparing them for a workout later in the year. Proper protection, cleaning, drying and sharpening and storage can make a big difference in seasons to come.

Mistletoe: Friend or Foe?        
Mistletoe has long fascinated people and has played both good and bad roles in various mythologies. For instance, in Norse mythology, it represented a peace symbol. Herbalists have used it medically, but the berries, which are nestled in the scale-like leaves, are known to be poisonous to both humans and pets. These days, mistletoe has a pretty good reputation around Christmas time. It's commonly associated with romance. Walk under it, accidentally or intentionally, and you'll likely find yourself getting a kiss. Rich in symbolism of harmony, mistletoe at a glance seems to be a plant of virtue. In fact, the mistletoe was selected as the Oklahoma State Flower in 1893, some 14 years before statehood. In 2004, it was changed to the Oklahoma State Floral Emblem when the Oklahoma Rose was designated the State Flower.

Unfortunately, an investigation of its home before the household doorway or ceiling will uncover a tainted past. Our variety of mistletoe is actually a parasite to more than 100 types of shade trees and evergreens.  Mistletoe is an evergreen tree-dwelling shrub often found in the upper branches of trees where there is plenty of sunlight for photosynthesis. It is spread by birds (robins, thrushes, and bluebirds) that eat the seed-containing berries found on female mistletoe plants, then excrete the white sticky berries onto the limbs. Instead of roots, mistletoe plants produce finger-like projections, called haustoria, which grow through the tree bark and into the tree branches. Making a connection with the water-conducting vessels of the tree, mistletoe absorbs the water and minerals it needs to grow and reproduce. Some mistletoe species grow only a few inches in diameter while others grow into impressive masses measuring several feet across. Under such stress trees infected with large amounts of mistletoe often become weak and tend to decline over a period of years. The area where mistletoe connects into the tree becomes swollen and distorted and, over time, these weakened branch areas often die and break.

The best way to control mistletoe is by cutting out infected branches below the point where it's attached to the branch. In large trees, this may involve extensive pruning and should be done by a professional arborist. If the mistletoe is merely broken off at its roots' connection to the tree, it will regrow. However, some people have prevented regrowth by covering the roots with plastic wrap. Another approach is the use of a chemical called Ethephon, which is sold as a Florel-brand growth regulator. It is a relatively non-toxic compound that produces a plant hormone, ethylene, which causes the mistletoe to drop its leaves when properly sprayed in late winter during tree dormancy. More than one spraying may be required for heavy infestations.

Though an unwelcome visitor in trees, mistletoe will likely continue to be welcomed into homes as a holiday tradition and promoter of romance. So, watch where you walk!
For more information on this, or any related horticulture subject, contact a Master Gardener at the Tulsa OSU Extension office.

Question: Will ice melt products harm my plants and lawn? 
Answer: Products used to melt ice on walks and driveways may harm plants, but this depends on what and how much is used. Most of the chemicals marketed to melt ice are salts that lower the freezing point of water. All are useful if the labeled directions are followed carefully.

Four of the most commonly used chemicals are sodium chloride (table salt), calcium chloride, calcium magnesium acetate and urea. All are salts except urea, which is a chemical normally found in fertilizers.

These products thaw ice but also have some undesirable effects. They may cause corrosion of concrete and metal, water pollution, as well as harm to plants.

Sodium chloride is the cheapest and most widely used for ice melt. It has a significant potential for corrosion and plant damage in high concentrations. Calcium chloride and urea have similar risk for corrosion but are less harmful to plants. Calcium magnesium acetate does not corrode or pollute water and does not harm plants. It also is the most expensive.

Damage to plants occurs in two ways - directly when splashed on plants and secondarily when absorbed into the soil. When slush containing salt comes in contact with a plant, it may cause direct injury to both evergreen leaves and buds, and stems of deciduous plants. This injury, especially in deciduous plants, may not appear until spring.

Salts that filter into the soil can kill plant roots by dehydrating them. This is the same as fertilizer "burn" gardeners are familiar with. In addition, large amounts of sodium from sodium chloride can damage the soil structure, making it less friendly to plants.

The ideal approach to ice and snow is to remove as much as possible by hand and then, if you feel it is needed, apply an ice melt chemical to help remove the last layer. Avoid the "more is better" mindset, and follow the labeled directions. Mixing sand 3 to 1 with ice melt can reduce the need for chemicals, the added sand gives traction to feet and tires.
Harmful effects of these chemicals may be minimized by hosing salt off plants, when possible. Much of the salt in soils may be removed if irrigated with generous amounts of water. We are fortunate that ice and snow are not long-term winter problems in our area and that most people are able to cope without ice melt chemicals.

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