December 2015 / Volume 105     

In This Issue

Weather Stats for Gardeners

Soil Temperature 2" below sod:   

47 degrees 


Rainfall total last 30 days:  

7.92 inches

Rainfall total YTD: 

56.48 inches

(Last Year: 27.56 inches)


Donations Keep The Tulsa Master Gardener Program Going Strong
Recognition of this month's donations:

At the November General Membership meeting, it was announced that membership dues are no longer required, but volunteer donations are still be very much welcomed . . . and appreciated.  At that meeting, a total of $1,760 was collected from a multitude of generous Master Gardeners (very sorry, but too many names to keep track of).  Soon thereafter, at the November Foundation Board meeting, another $250 was contributed by board members.  Since then, additional donations have been received from:

Harold Springer
Marie Garrison
Dean Reiss
Dianne Nail
Robert Mickey
Terri Cain
Phyllis Dewitt
Jeannie Alaback
Mary Pittman.  

A BIG THANKS TO EACH AND EVERYONE ONE OF YOU for helping to keep the MG program going strong!
The Tulsa Master Gardener Foundation receives no city, state or federal funding for its programs. In fact, the majority of Tulsa's Master Gardener programs are self-funded. While we have many dues-paying members, income received from dues pays for less than 5% of total annual expenses. 

Tulsa Master Gardener's own fundraisers make up most of the income to cover expenses. A significant portion comes from the Tulsa Master Gardener annual plant sale that is held each April. Other fundraisers include the Garden Tour (June) and "garage sales" that occur from time to time. However, one other income source that sometimes gets overlooked is  personal and corporate donations.

To find out how you can help support all that the Tulsa Master Gardeners do for their community, contact the Tulsa Master Gardener office directly. 

4 Ways to Contact Us
Email us at:

See our website at: 

Call: 918-746-3701 from 9-4, Monday - Friday 
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.
December Garden, Lawn, & Landscape Tips
  • Cover strawberry plants with a mulch about 3 to 4 inches thick if plants are prone to winter injury.
    Keep all plants watered during dry conditions even though some may be dormant.
  • Wait to prune fruit trees until late February or March.
  • Irrigate all plantings at least 24 hours before hard-freezing weather if soil is dry. (HLA-6404)
  • Order gardening supplies for next season.
  • Now is a great time to design and make structural improvements in your garden and landscape.
  • Send for mail-order catalogs if you are not already on their mailing lists.
  • Christmas gift ideas for the gardener might include tools, garden books and magazine subscriptions.
  • Clean and fill bird feeders.
  • Make sure indoor plants are receiving enough light, or set up an indoor fluorescent plant light.
  • Till garden plots without a cover crop to further expose garden pests to harsh winter conditions.
  • Visit your county extension office to obtain gardening fact sheets for the new gardening season.
  • Join a horticulture, plant, or urban forestry society and support community "greening" or "beautification" projects.
  • Review your garden records so you can correct past mistakes.  Purchase a new gardening journal or calendar to keep the New Year's gardening records. 
  • Remove leaves from cool-season grasses or mow with a mulching mower. (HLA-6420)
  • Continue mowing cool-season lawns on a regular basis. (HLA-6420)
  • Continue to control broadleaf weeds in well-established warm- or cool-season lawns with a post-emergent broadleaf weed killer. 
  • Apply winter mulch to protect rose bush bud unions and other perennials.  Wait until after several early freezes or you will give insects a good place to winter.
  • Poinsettias must have at least six hours of bright, indirect light daily.  Keep plants away from drafts.
  • Select a freshly cut Christmas tree.  Make a new cut prior to placing in tree stand.  Add water daily. 

  • Live Christmas trees are a wise investment, as they become permanent additions to the landscape after the holidays.

  • Light prunings of evergreens can be used for holiday decorations.  Be careful with sap that can mar surfaces.


Tulsa Master Gardener Program of the Month
Horticultural Therapy Projects
"Sowing Seeds of Change"

Since as early as the 1800's, the calming effects of the people-plant connections through Horticulture therapy has been used to treat mental illness.  Today, hospitals and rehabilitative centers across the world use horticulturally-therapeutic landscaping and programming to treat both physical and mental disabilities.  From  TBI's (Traumatic Brain Injury) to strokes, from the elderly to the incarcerated, and even to those with PTSD evidenced-based horticulture therapy has been effectively used to treat the fine motor, gross motor, social, cognitive, emotional and behavioral challenges that those living with mental illness face.*  Even staff gravitate to the calming mood elevating effects of plant-filled spaces.
Amid all its benefits, Horticulture therapy enables those with cognitive challenges (for instance) to improve their ability to correctly sequence multi-step tasks or, for those who are emotionally challenged, to improve their ability to self-monitor. Likewise, the physically-challenged are able to improve both physical endurance and bilateral integration of upper and lower extremities (just to name a few).
Additionally, successful food/ flower production could subsidize budgets and serve as prevocational therapeutic training that may enable them to work in environments where the participant may feel more comfortable.  Having Master Gardeners as coaches, guiding the experience of group members further enhances their experiences and reduces frustrations.
Just last month, Tulsa Master Gardeners sowed two raised beds into the lives of the disabled veterans that would utilize them.  On that rainy day, I witnessed Veterans that had not freely communicated with strangers since before the onset of their trauma, chatting, asking questions, and making small talk with Master Gardeners whom they had never met.  The Master Gardeners were respectfully empathetic, did not talk down to them, nor get inpatient as some struggled to formulate their ideas into words.  These veterans found common ground and acceptance with strangers.  Had the Master Gardeners merely hosted a talk on raised beds, it is doubtful that these instant connections would have occurred.  
But their work did not begin with veterans, Tulsa Master Gardeners have been sowing horticulturally-therapeutic seeds into the lives of Crossroads Clubhouse participants for some time now.  Crossroads, a non-profit organization dedicated to providing rehabilitation and support to those living with severe mental illness, welcomed the collaboration with Tulsa MGs.  Sessions that promote mindfulness, social integration, sequential instruction, patience, and the calming effects of "living color" have been instrumental with the implementation of recovery plans that promote community reintegration.
The connections made through horticulture, and specifically community horticulture, stimulates positive social relationships through such things as community socials, collaborative plantings, and food preparation activities.  As group members build capacity and expertise through experiences, they build confidence, which is the platform for them to "sow it forward".
Horticulture Therapy, if sown, is the seed that can reap a bountiful harvest.

* (Digging for Victory: Horticultural Therapy with Veterans for Post-Traumatic Growth by Joanna Wise)

Weather Update: Strong El Nino Year Ahead?
For those that just want to know the answer . . .

The most likely scenario is for a more active storm track this coming winter, resulting in above normal precipitation.  Since we are heading into winter with basically saturated soils, moisture deficits are not likely to be an issue, which means less winter landscape watering - just beware of root rot in certain sensitive perennials.  As for snow and ice, no historical correlations between Tulsa snowfall and El Ni�o are really worth noting.  So, just keep your eye on the weather forecasts and always take the Day 3 through 7 forecasts in the winter with a large grain of salt - hopefully, you have such on hand just in case you need it!

For those that are craving more information . . .

December has arrived, which means that winter is officially here! The weather world has been all abuzz about things going on in the Pacific Ocean nearly half a world away from Tulsa.  But why? Sure, the water is unusually warm along the Equator, off the South American coast, but what does this have to do with winter weather in Tulsa?  Most of you actually know the answer to this question.  The phenomena known to us all as El Ni�o is raging in the Pacific as we speak, and signs continue to point to this being an historic one.

Because the oceans and atmosphere closely interact, changes in the ocean temperatures can, and often do, have a significant impact on weather in regions that are far removed from the temperature anomaly. El Ni�o is by far the best understood of these phenomena, and tends to occur in fairly regular cycles. Thus, there is a fair amount of historical data to draw from, for comparison's sake.
El Ni�o, being basically an area of abnormally warm ocean temperatures along and near the Equator in the Pacific Ocean, causes a substantial change in the Jet Stream through mainly the winter months in the northern hemisphere.  This, in turn, has a pronounced impact on winter weather in certain regions.
The most important impacts for the United States are a strong Subtropical Jet Stream across the south, and a shift of the Polar Jet to the northeast. The tendency in El Ni�o years, then, is for a more active storm track in the winter across the southern U.S., and a tendency for fewer outbreaks of Arctic air in the lower 48. The overall historic impact has been increased likelihood of above normal winter precipitation in this area, but not necessarily much of a tendency either way in mean temperatures.
What most people want to know is - will we see more snow and ice than usual this winter?  Well, we have already seen the active southerly storm track set up in November, resulting in Tulsa's 4th wettest November on record (bonus: we just missed out on an ice storm Thanksgiving weekend by about 3 degrees, or 50 miles). It can't be said absolutely for sure that this pattern will continue, but history seems to show that it's more likely than not, so frequent storm systems may well be in our future over the next few months.  Having said that, remember Tulsa is usually right on the cusp of where things transition from rain to ice to snow (thanks to our geography), which is what makes Oklahoma weather so darn fun!


Composting: A Very Smart Idea
Fall leaves are a valuable resource because they keep garden soil productive.  By following a few tried and true composting techniques, you can optimize fall-leaf composting.  

Size: The minimum size for compost bins is three feet by three feet by three feet. Bins larger than six feet across may restrict oxygen infiltration and slow decomposition.

Mixture: It's best to mix some nitrogen into the leaves as you add them to the compost.  Leaves are high in carbon, which makes great compost, but they're comparatively low in nitrogen (which is what decomposing bacteria feed on).  You can add nitrogen in the form of fertilizer or fresh green organic matter.  Just add one-quarter to one-half cup of standard lawn fertilizer per bushel or add one part dry leaves with two parts fresh grass clippings or similar green garden debris.  If you use a fertilizer, be sure to select one that contains no weed killers.  Chicken, rabbit or horse manure also are great sources to get that pile of leaves heated up and cooking.  As for how much of each to add, just use another good rule of thumb - the 5 to 1 ratio.  For every 5 wheelbarrows, buckets or bags of shredded leaves you add to the pile, mix in 1 wheelbarrow, bucket or bag of cut grass clippings or manure.  As you add leaves to the compost, moisten them until they're the consistency of a wet sponge.  Check the compost regularly and water to maintain adequate moisture content.  Moisture is slow to soak through a leaf pile, but is essential for decomposition.  Be careful not to over-water (you don't want the leaves to be soggy).

Leaves: Although leaves are plentiful this time of year, some are better than others.  Maple, birch, ash, and fruit tree leaves are fantastic to compost.  Do not add walnut leaves to a compost pile as they contain material that affects the growth of certain other plants. Oak leaves should be composted in moderation, as they tend to be more acidic.

Heat: If you want that pile to get heated up and compost even quicker, turn your pile with a shovel or pitchfork a few times each week.  It doesn't take great effort, especially with the light make-up of a leaf compost pile.  However, turning that pile and mixing in oxygen gets it to heat up and break down very quickly.

Uses:  The falling leaves and resulting compost that are made with them are a great way to obtain huge amounts of "black gold" (the affectionate name many gardeners give to compost for it's value to a successful garden).  Compost makes all the difference in helping to grow healthy plants.  Mix in generous amounts to the soil when planting vegetables, perennials, shurbs and trees in the landscape.

Healthy Soil = Healthy Plants.  There is no quicker way to healthy soil than using lots of great compost.

For more detailed information, please refer to two OSU fact sheets on this subject, as follows:

BAE-1744; Backyard Composting in Oklahoma

L-252: Composting - A Great Way to Make the Most of your Leaves

Using Leaves as Mulch
As an alternative to the composting method described above, here is another way your leaves can be used for horticultural purposes vs disposing of them in the trash.

First, use a rake or power blower to get all of your leaves out from under your bedding plants and all of your shrubs and pile them on your grassy areas.  Put your lawn mower in the "Mulching" mode, making sure the mowing height is above the grass level, then run the mower over your leaves.  

Then, put the mower in the "Bagging" mode and re-mow the bits of leaves covering the grass.  This will chip the mowed leaves by cutting them into even smaller pieces.  You can now use these small pieces to mulch flower beds and shrubs or anywhere you need mulch.  Any leftover leaf bits can then be put in black trash bags and placed in a sunny location.  The heat from the sun will help kill any pests.  Use these bags later in the year to replace the earlier, but now decomposed, mulch. 


Winterizing Garden Tools
As temperatures drop and we prepare ourselves for spending more time indoors, don't forget to prepare your garden tools for use next spring.  Keeping your garden tools sharpened, polished and cleaned will help you get a jump start on your landscaping duties next year.
Shovels, rakes and hoes - Clean using a wire brush and some soapy water.  After cleaning dry them thoroughly and store them away.  If your tools are dull, sharpen them using a whetstone or a file.  Make certain to start at the outer edge of your tool and move toward the center.  Remove rust spots with sandpaper or steel wool, then coat the metal portion with vegetable or linseed oil and wipe a light coating of oil on the wooden handles.  The oil will help preserve them and prevent cracking and/or splitting. 

Sometimes a sand bucket is used to clean tools.  To make a oil and sand bucket, fill a clean, five-gallon bucket with sand and add a quart of oil.  Some use motor oil, while others use linseed oil and some prefer an organic alternative such a vegetable oil.  To use it, simply dig your tools in and out.  The abrasive sand cleans the tool by removing rust and debris.  An alternative to the oil and sand bucket is to use a five-gallon bucket filled with moderately wet sand.  It is used the same way, except the tool must be oiled after use.  If you choose, tools can be kept and protected in the bucket of sand all winter.  Otherwise, hang with the "working end" up in a dry location.
Pruners, pruning saws and loppers - Remove rust with a wire brush and sharpen pruners and loppers with a whetstone.  If you have small nicks, remove them with a fine file.  Alternatively, save yourself some time by dropping off your pruning saws at a hardware store to have them sharpened for you for a small fee. Some pruners have replaceable parts.  In this instance, disassemble, clean and replace any worn out parts.

Now that any grass, soil, roots, tree bark and any other foreign substance is removed, it is time to pay attention to bacteria, fungi and weed seeds.  This is done by disinfecting with a 2% solution of common household bleach.  

Mowers, tillers, chain saws, blowers - Run mowers as late in the season as possible in order to use up all of the fuel in the tank and pick up the last bit of fallen leaves.  A handy trick is to use a turkey baster to suck out most of the fuel before running it out. If you choose to leave fuel in the machine, be sure to add fuel stabilizer.  Avoid storing extra gasoline in containers over the winter - fresh fuel in the spring is always better for the machine. Using a hose and wire brush, remove any caked-up soil, grass and leaves.  Check your mower blade for any nicks and chips and sharpen or replace the blade.  Make certain to inspect your wheels and height adjuster.  Wipe down and oil the mower as necessary.  Check the chain on your chainsaw and make certain to either sharpen or replace it and don't forget to change the spark plugs.  

Sprayers and spreaders - For those used for insect, disease and weed control, simply wash and rinse all parts of the container thoroughly, including the holding tank and nozzle.  It may take several times to ensure that the pesticides are removed.

While you are working with sprayers and spreaders, now would also be a good time to check expiration dates on lawn and garden chemicals, making sure you are complying with manufacturer storage recommendations.
Wheelbarrows, wagons, hoses and carts - Clean the items carefully and, if you find there is chipped paint, try spray painting to prevent rusting in the exposed area.  Make certain to grease wheels.  For water hoses, make certain to remove kinks to prevent weak points and cracking in the hose.  Remove the excess water from your hoses, store in a dry location and on a support or reels loosely to prevent sagging. in a dry location.

Don't wait until that dark and damp night the weatherman tells you there is a freeze warning.  In fact, five days to two weeks earlier is ideal.  So, plan ahead now!  Then, you can s
it down in the easy chair, pull out those seed catalogs, and fantasize about next year's garden between snoozes.  YOU'VE EARNED IT!


Poinsettia Care          

Fragrant evergreens, twinkling lights and the flaming beauty of poinsettias (Eupitorbia pulcherrima) are a colorful part of the American Christmas tradition.  This is mostly due to the importation of this tropical plant by Joel Poinsett, the first ambassador from the U.S. to Mexico.  This well-educated gentleman was a physician, diplomat, member of Congress, U.S. Secretary of War, and co-founder of the forerunner of the Smithsonian Institute.  As an avid amateur botanist, he sent samples of the plant back to the United States in 1823.  In Mexico, it is known as "Flor de Noche Buena" (Christmas Eve flower).

Poinsettias can be fickle plants and gardening novices may find them challenging to maintain.  They are composed of green foliage, colorful bracts (specialized leaves) which surround the true flowers that are the button-like yellow or green parts nestled in the center.  When buying a poinsettia, choose a plant with well-expanded, well-colored bracts.  Foliage should be medium to dark green with uniform coloring.  Flowers should be present in the center but, ideally, still mainly closed with little pollen present.

After purchasing your plant, do not expose it to chilling temperatures or cold drafts.  If the outdoor temperature is below 50 degrees, protect the plant on the way home.  When placing it in your home, avoid heating ducts, fireplaces, and large lamps.  Do not allow plants to make contact with windows, as cold glass may injure it. 

Light plays an important part in retaining leaves on the plant.  It will need at least six or eight hours of direct natural light or artificial light. 

The plant could be displayed with other houseplants as the adjacent plants will raise the air's humidity and thus prolong leaf retention. 

It is sometimes difficult to know when to water poinsettias.  If it has been planted in a medium that does not contain soil or sand and is in a plastic pot, try lifting the pot.  If the plant is heavy, there is usually enough moisture in the pot.  If it is lightweight, the planting medium is dry and a thorough watering should be given.  As a general rule, feel the top of the growing medium.  If it is dry, you should water.  Do not allow too much drying out.  Slight wilting of the plant is not harmful, but avoid severe wilting, which will cause leaves and bracts to drop sooner.  To water the plant thoroughly, make sure a small amount of water drains out the bottom of the pot.  If it is wrapped in decorative foil, punch a hole in the foil for drainage and place pot on a saucer.  Do not allow pot to sit in standing water. A well cared for plant should remain attractive in the house for about eight weeks.
According to recent research, poinsettia plants are not poisonous.  However, some people are sensitive to the milky sap of the plant and may have an allergic reaction to it.  As with any houseplant, keep it out of reach of small children and pets.  Most individuals agree that it is easier to discard a poinsettia after the bracts fall and buy a new plant next year.  Attempting to coax re-flowering is a tedious process.  

For more information, see  OSU Fact Sheet HLA-6413 for details.


Southwest Injury / Sunscald

Southwest Injury or Sunscald is a wintertime injury to tree trunks, caused by the sun's warmth and freezing temperatures.  Young, thin-barked trees including the maples, redbuds, willows, crabapples, ashes, honeylocusts and fruit trees are most at risk.  
Trees that are under stress due to environmental factors, herbicide injury, and or insect and disease are also susceptible to damage.  

How it happens is when we have a warm, sunny day in January and the sun is at a low-angle and it warms the south and southwest sides of the trunk causing cold-hardy bark cells to warm and expand.  Then, the sun sets and the temperature drops below freezing and the bark cells are killed, causing the bark to split.  Water flow from the roots to the top of the tree can be affected by the split and the top of the tree may also suffer from die-back.  Trees planted on the east or north of buildings are less likely to be affected.
It is possible to prevent Sunscald on young trees for the first two or three winters by placing a board on the southwest side of the trunk or by using a tree wrap product purchased at local nurseries.  Start at the bottom of the trunk and overlap by one third on each pass to allow water to run off the wrap.  Wrap up to just above the second branch and secure with stretchable tape.  Wrapping in November and removing the wrap in April will prevent Sunscald in the colder months and insects or disease being harbored under the wrap when the weather warms.

Sunscald is not a summer problem because leaves protect the tree trunk from sun, the sun is higher in the sky and freezing temperatures are not likely.