Most of what we think about in regard to trees is how they affect us over the next decade or so, but in reality we are more like caretakers for trees that dozens of generations of people will sit under.  Kind of changes the perspective, doesn’t it?  When you’re thinking about tree management or trimming your trees, try to think long term instead of short.

Keep that in mind while you read this article.  You’ll find part of it below, but the rest of it is here.  Let’s all try to keep our trees so that many other generations can enjoy them.

“A celebration is planned in the Central Texas town of New Braunfels for a massive live oak believed to be more than 300 years old.

The sprawling tree named Founders’ Oak will be honored Saturday. The Texas Forest Service in June declared the tree with a trunk exceeding 17 feet in circumference a “Famous Tree of Texas.”

Gretchen Riley of the Texas Forest Service tells the San Antonio Express-News a tree must have witnessed significant events in Texas frontier history to get the designation.

The Forest Service profile says the tree “has stood sentry to centuries of travelers and settlers to the Guadalupe River region.” In the 1750s, a Spanish mission was located nearby.

The tree, there when the city was established in 1845, has become a beloved landmark.”

First of all, never stand under trees for protection in a thunderstorm.  Go ahead and get your car interior wet, it’s better than death or a nice hospital stay.  Like this story of lightning striking a Texas tree in Houston, these guys hid under the trees to protect them from the rain, only to meet a tragic end when lightning followed it’s natural instinct and struck at the highest point around.  Now, what’s interesting is that as it struck, it blew all the bark off the tree.  This is a commonly reported effect, but why does it happen?  Let’s look.

What many homeowners in the Austin area don’t realize is that trees have a vascular system much like our own.  Only unlike ours, the main functioning part of a trees xylem and phloem is located in the outer 1/8 inch or so of tissue.  Most if the interior of the tree is dead tissue.  Since the material being transported in this area is relatively high in electrolytes, it conducts electricity much better than the surrounding tissue.  As the hundreds of thousands of volts shoot through it, the vascular system is super heated, causing it to rupture violently, causing the bark to fly off in a spectacular display.  This is much better viewed at a distance than to see it up close and personal.

If you have tall trees in your Austin landscape, or any trees at all, don’t think of them as protection in a Texas thunderstorm, think of them as excellent conductors for lightning, and get far, far away.

Trees are like most other organisms, in that they have a vascular system.  From the smallest root hairs to the very tip of the top leaf in the tree, there is a system to move water and nutrients throughout the entire entity.  Water, of course, is the core of this system, and the lack of water means big problems for your trees.  If a little lack of water is bad, what does it mean if you tree goes througha  historic drought?  In short, it’s bad.  Possibly even lethal.  This is why we’ve had to do so much tree removal for our Austin area clients this year.

Just like humans, the vascular system of trees begins to break down at a cellular level without adequate water.  Trees have a self defense mechanism that kicks in immediately upon onset of less than adequate water conditions.  Incidentally, we get calls on a regular basis from our Austin tree service customers asking about live oak leaves doing what’s called “cupping”, or seeming to wilt. This is just one of the self protective measures that the tree is taking to keep water inside the tree.  The stoma on the underside of leaves close, causing the natural vaccuum system to begin to “cup” the leaves.  It’s not bad, it’s actually good.

Now, back to Tip Dieback.  As the vascular system breaks down, the tree shuts down food and water at the tip, because that’s the hardest area to keep alive.  Tip Dieback is not something to try to correct, but a reflection of a problem that is ongoing.  It’s the result, not the cause.  You should call a professional to see what can be done, but usually, all you can do is to ensure adequate water from that point forward, and hope for the best.

Did the drought kill your trees?  The answer might surprise you; no.  What the drought did was to severely weaken trees that had reached far into maturity, causing them to be susceptible to many different threats that they normally would not be at risk from, such as insect invasion, disease, etc…  This points out why it is so important to keep your trees hydrated, even in drought or low water conditions.  What ever you have to do, it is worth the investment.  You just can’t replace a mature tree in a Texas landscape, the shade is just too valuable.

In a great article by NPR,  Terrence Henry talks about the loss of hundreds of millions of trees in Texas to the drought, and how that is and is not a direct cause.

The numbers of trees estimated to have been lost to last year’s drought were, in a word, troubling. Up to ten percent of Texas’ urban trees were thought to be lost, a total of up to five million. In the forests the situation was the same, with up to ten percent — 500 million — of Texas’ trees estimated to be lost.

But the drought may not be entirely to blame, according to a new report by the Agrlifie Extension Service at Texas A&M University.

“Drought is the primary contributor to tree kill, but it may not be exactly the way you might be thinking,” Dr. Eric Taylor, Texas AgriLife Extension Service forestry specialist, Overton, says in the report. “You may find this hard to believe, but relatively few trees likely died directly from dehydration in 2011. Instead, the 2011 drought severely weakened mature trees, making them susceptible to opportunistic pathogens like hypoxylon canker and insects like pine bark engraver beetles.”

As the extreme heat and drought of stressed-out older trees, they stood less of a chance against the opposition. “Just like humans, a healthy organism is able to fight off the problems that are trying to come in and attack them,” says Jim Hauser, a Forest Health Coordinator with the Texas Forest Service.

The report says that in most cases, the trees lost to the drought “were already stressed from a number of pre-existing environmental factors such as overcrowding, growing on the wrong site, age, soil compaction, trenching or inappropriate use of herbicides. If not for these factors, a large proportion of the trees that died might have recovered from the drought.”

(Read the rest of the article here)

I dug a little deeper.  I asked him to tell me what had happened over the last couple of weeks, and the last few days in particular.   He told me about a few things that didn’t warrant anything as severe as leaves falling off, like miscellaneous small plantings, grass raking, etc…  I knew that wasn’t enough, so I asked further.

Turns out that he had planned to fertilize his grass, which was chronically sparse in this shady area.  Now, at this point, I should add that this was a very large tree, especially for a residential area.  The canopy covered the entire front yard, plus some.  Since his grass was sparse, he had a lot of weeds.  Lots of weeds means you need to get rid of them, and a great way to do that is to use pre-emergent herbicide  to keep the seeds from germinating.  Here’s where it gets interesting.

In a very “I’m gonna fix it good this time”, typical man attitude, he used the tried-and-true “if some is good, more is better” approach, and tripled the amount of pre-emergent recommended for his yard size.  This put the tree into shock, and caused it to drop all of its leaves.  My friend thought he had killed the tree, and in truth, he’s lucky he didn’t.  I recommended heavily watering the area every 3-4 days.  Since the tree was already transpiring (processing) the pre-emergent, there was nothing we could do to stop that, so it made sense to simply flush the area and let the tree work through the shock process.

Now, there’s three key mistakes he made:

• 1) too much pre-emergent.  Never do that.  You can always put more, but you can never use less.
•  2)valuing the grass over the trees.  You can re-sod an entire front yard in a typical suburban landscape for a couple hundred dollars worth of sod, but a mature tree is really priceless.   It’s almost impossible that you’ll replace it in your lifetime.
• 3) not understanding that his landscape is tied together.  You can’t treat grass as if it is one plant, a tree another, and a flower bed yet another, but I continually see this in homeowners.  Remember, anything you do to one or another organism in your home landscape affects everything else.

Managing your landscape is a top down process.  To effectively manage your landscape, you must start with your trees.

First, it’s important to know what kind of trees you have in your landscape.  Watering needs vary from tree to tree, and this can cause you to either under-water your trees or even over-water them. Either case is bad.  How do you determine the type of tree you have in your yard?  You can usually clip a branch and take it in to a local nursery, and a landscape professional there can tell you.  You can also call a local tree service company, and they will send a professional out to check out your trees.  This will probably cost you some money, but think of it as an investment.  Be sure to ask if your trees have a tap root or not, this is very important.

Next, in watering your trees, think long-term in strategy and time commitment.  Slow watering is critical.  Why is this so important?  It’s because you’re not trying to just “get the ground wet”.  You have to be committed to fully watering the root system of the tree.  If your tree has  a 35 foot canopy, then you potentially have a 52 foot root spread.  Now, trees typically have a 18-24 inch deep capillary root system, so that’s the depth you need to reach.  There are some deep watering tools available that can help you get below the surface.

Finally, be patient.  Again, you’re playing a long game with your trees.  If you have old growth trees in your landscape, there is a good chance that they have been there for 50-100 years, so you really are caring for a multi-generational organism in your possession.  You have a legacy you can leave behind if you care for your trees correctly.