On Sun, 07 Sep 2003 22:46:22 GMT, (Terry Horton) opined:

Sun scald from lost foliage is always the biggest potential issue with
mid-summer pruning. Lateral buds forced by hormone levels thrown
askew would be another. And I suspect wound closure is far less
efficient under heat and water stress. Maybe one of the arborists
here can tell us more...

Ah, yes, this is something I'd not considered. Removing the apical dominance at
the tip would certainly not only stimulate new buds which will be lost, but you
are correct on the sun scald. I had not thought of that.

It has always been axiomatic that Texas summers are more stressful to
trees than our winters. With global warming and the blazing last
couple of decades, the difference is probably even greater (the nearby
Chihuahuan Desert and Trans-Pecos suggests our trees were already on
the climatic brink). One anecdotal tidbit... an arborist I know who's
been in the business for many years, says that his tree calls used to
be mainly disease related; now the overwhelming majority turn out to
be heat stress.

I'd imagine that, and the incorrect way people water. Five minutes a day is
horrible. It is much better to water for a few hours once a week and put down
at least half inch to inch of water so it can percolate a minimum of eight
inches.

Very sorry, V, I've been unable to backtrack to the original story.
One of those items that seemed to make biological sense, that I
distilled and filed mentally for future use. So, like I said,
fwiw..:-)

Yes. Your explanation makes perfect sense. I'm not thinking on all cylinders!

One of the largest oak wilt centers in Travis county is right across
the creek from us (the creek probably saved our oaks from root graft
infections). Cutting down and grinding up live oaks is a dark, busy
industry over there. And our own wild oaks, like all unirrigated
central Texas trees, have really suffered from drought stress the last
few years. Each year they're showing more branches in need of pruning
than ever before. I just feel I have to get every advantage and take
every precaution I can for them, large or small.

Absolutely. I agree fully. I find the best way to water the older and younger
trees is by using the cheap yellow circle sprinkler. It doesn't move, it has
many holes in concentric circles (2) on the top and the water goes up and drops
down in large droplets. It evaporates much less than the blazing mists put out
by high pressure sprinkler heads. I am always curious why people install
irrigation and don't use impact heads. They are so much more efficient because
they can be set to almost run parallel with the turf, larger drops, not much air
to ground evaporation.

Water deeply once a week. It usually takes me an entire day to water my whole
property. I have been using soaker hoses on the lawn and for the trees, lately.
I know it's a lot of lugging, but it has been very, very effective. Nothing
lost to air evap.

Have a peaceful night and a positive week,
Victoria