CROSS TIMBERS HORTICULTURE
A newsletter for Texas Agricultural Extension District 8 and parts of 3,
4 and 7!
Nancy Roe, Extension Horticulture Specialist
WHAT TO PLANT IN MARCH
(modify for your location if necessary)
VEGETABLES
Growers in the northern parts may still be able to plant root crops and
cole crops early in the month. Others may need to side dress cool season
crops with nitrogen-growth rates should increase as days get warmer (?)
and longer.
Be sure summer vegetable producers have their soil tested to know what nutrients
they need to add. We also need to have this information as we begin collecting
test results to calibrate soil tests and improve our recommendations.
It's OK to plant tomatoes early if you have a way to protect them from cold
spells, but don't try to push the season with peppers.
Most cucurbits need a minimum of 60 degrees soil temperature to germinate-and
they're happier with 85 or 90. So, if growers are not using a black mulch,
in most of your counties, they should wait until at least April for these
crops.
PECANS
Trees which have shown evidence of phylloxera galls should be treated with
Lorsban, Thiodan, Lindane, or Malathion when new growth is about 1-2"
long. An alternative is the use of dormant oil before bud break.
Central Texas Pecan Shortcourse is at Goldthwaite on March 26.
FRUIT
Most of you know that the early season sprays are critical for good insect
and disease control on tree fruit. Remind homeowners and new growers that
when they call us in July to tell us their peaches have "worms",
there's nothing that can be done!
HOME LAWN AND GARDEN TIPS
Pre-emergent herbicides in lawns need to be applied immediately-it may be
too late in some areas to catch some weed species before they germinate.
The lack of rain may give us a longer window, though.
Tent caterpillars and webworms can be controlled with BT's-if you can reach
them with the sprayed, and IF they are sprayed when the larvae are eating
outside the nest.
I've had some questions about fertilization of homeowner pecans. Here is
what Larry Stein recommends: "if the soil pH is above 7.0 , use only
N as a general rule of thumb; and use 1 pound of N fertilizer per inch of
trunk diameter at breast height. Make your measurement in early spring
and then apply this amount of fertilizer over 2 or 3 applications, ie.
March, April and May. This is in addition to the fertilizer which is being
applied to the grass. If the soil pH is below 7.0, then the first application
can be 3-1-2 ratio fertilizer such as 15 - 5 - 10. If the trees are making
8 - 10 -12 inches of growth on this system, then the amount is about right;
only about 2 - 3 inches of growth then more is required; and over 3 feet
of growth, then way too much fertilizer is being applied. Adjustments can
then be made accordingly."
Feed roses every 4-6 weeks until early or mid August. An 8-8-8 at 1.25 lbs/100
sq ft is recommended in our rose publication. However, Dr. Bill Welch has
suggested to me that this is another case where we are probably building
up nutrients. Rose beds which have been fertilized several times with
complete fertilizers, especially in high pH soils, may not need any more
phosphorus or potassium. He suggests using ammonium sulfate or cottonseed
meal. A cup or two of the cottonseed meal may be sprinkled around each bush
in late winter and again in early summer.
For black spot control, as soon as the leaves have emerged, it is necessary
to spray fungicide (Daconil, Funginex) every 7-10 days during humid periods-which
may be most of the summer in certain areas or years.
ORGANICS
One method sometimes recommended for organic control of aphids and spider
mites is washing them off the leaves. In 1994 Extension Entomologist Dr.
Bart Drees tested 2 "high pressure water spray devices for insect
and mite control". They were the Water Wand for Spider Mites and the
Jet-All Water Wand. These devices are attached to a hose and direct high
pressure spray upward so that the undersides of leaves can be sprayed. Dr.
Drees reported that the water WWSM and Jet-All reduced aphid counts by
56% and 69 %, respectively, and controlled aphids on 28 and 30% of the leaves.
When tested on miniature roses with spider mites, the Jet-All reduced counts
from an average of 4.1 per leaf to 0.1 per leaf. Mite populations continued
to decline for 2 weeks. When aphids on the roses were treated, populations
declined immediately but reappeared within 2 weeks. A second treatment reduced
the populations again.
Dr. Drees does note that spray should be directed away from other potential
host plants, as the dislodged pests may infect them.
This is a treatment worth trying for organic gardeners who do not mind taking
the time to treat. It may be necessary to retreat periodically throughout
the season. Also keep in mind that we would want to do this during a time
of day when the water would evaporate, so that we do not encourage fungal
diseases.
STEPHENVILLE REC HORTICULTURE NEWS
As I write this, our strawberries are covered with row cover again-although
the temperatures predicted for this week are not as low as those earlier
in the winter, the plants are now growing rapidly and blooming so they are
much more vulnerable to cold.
Table Grape Pruning Demonstration for agents, growers, and homeowners is
on Thursday, March 28th at 3PM. Bring pruning equipment for hands-on practice!
I've made up a news release for anyone who would like one.
NEWS FOR YOU AND YOUR COMMERCIAL GROWERS
Dr. Cornforth and I have just finished writing a report on the work we
did last summer with dairy manure (lot scrapings) and dairy manure composts
on dry-land cantaloupes and an irrigated fall broccoli crop. Basically,
all the composts (10-40 T/A) and manure (20 T/A) increased yields over no
organic matter. An economic analysis showed that the manure provided the
biggest financial advantage. I know that commercial growers think they can't
afford to use organic matter. However, growers who are located close to
cheap or free organic matter sources may find definite yield and economic
advantages. Lower rates (2-5 T/A) may work as well as the rates we used.
This experiment will continue for 2 more years on the same plots.