A Texas A&M Forest Service survey of hundreds of
forested plots scattered across the state shows 301 million trees were killed
as a result of the devastating 2011 drought.
The figure does not include trees in cities and towns. Another 5.6
million trees in urban areas — along streets and in yards and parks — also died
as a result of the drought, according to a study done earlier this year by the
Texas A&M Forest Service Urban Forestry program.
As we hope that the current drought is coming to a
close and think about replacing trees that have been a victim of the drought,
some folks may consider the Live Oak Tree.
They are excellent landscape trees that contribute to property values in
all parts of the state.
When selecting acorns, consider taking them from the
most desirable trees native to the local area. Characteristics worth noting
when choosing a mature tree as a seed source are desirability of leaf color and
shape, drought tolerance, absence of galls, trunk form, vigor and
umbrella-shaped canopies. Growers should understand, however, that oaks are wind
pollinated. The undetermined pollen source in the formation of the acorn may
dilute the desirable characteristics sought, according to Austin Stockton and
David Morgan, formerly with the Texas Agricultural Experiment Station.
Acorns are collected in the autumn months, from
October to December. It is not uncommon for acorns to germinate while on the
trees. Ripe acorns can be picked before they fall; often it is wise to do so in
order to escape weevils (Curculio spp.) which attack those that fall to
the ground. Acorns that are brown in color are physiologically mature; those
which are yellowish are not ripe. As a rule of thumb, a mature acorn will snap
cleanly from its cup without leaving a tissue residue.
When checking for viable seed, discard acorns that float
in water along with those that show pin-sized weevil exit holes. Live oak seeds
frequently contain weevil larvae that prevent germination. Acorn viability is
adversely affected by dry storage. If acorns lose as little as 15% of their
initial moisture, percent germination may be reduced by one-third; 20% moisture
loss may reduce viability by 96%. This is why acorns that have been lying on
the ground for 2 days may not germinate. If stored in damp peat moss, acorns
will germinate and may remain healthy for a short period of time. After 4 or
more weeks storage in wet peat they will begin to rot.
Ideally, acorns should be planted immediately after collection. No
scarification or stratification is required; but any remaining cups should be
removed.
A well-drained growing medium is preferred for
germination in flats. Flats should be at least 6 inches deep. Covering the
bottom of the flat with copper wire mesh promotes an extensive, well-developed
root system. Seedling tap roots are killed when they touch the mesh, and
lateral branching is encouraged. This type of root system is deal for continued
growth in 1- and 3-gallon containers. Seedlings may be moved to containers
during the spring following fall germination.
If you have questions about planting trees, the Texas
A&M Forest Service has an excellent Tree Planting Guide that can be
accessed at the following web site; http://texastreeplanting.tamu.edu/
