Crape Myrtle show

After one of the hottest, driest summers Austin has ever seen, we finally got some rain last month. Not just a quick shower that disappears in minutes, but days of slow, steady soaking. For fans of crape myrtles ( Lagerstroemia indica), it was a sweet reward.

Crape myrtles are native to Asia, but they do well almost everywhere. They are tough, reliable trees that usually bloom all summer. In this year's heat, not so much. Irrigated trees in parking lots and commercial developments (and a few residences) bloomed, though perhaps not as boldly as in other years, but most of us saw few, if any, flowers. Finally, the rain changed that. For several days, it was hard to find a place in Austin that was not in view of a burst of blossoms on at least one crape. It was an amazing show.

A few of my friends

I've been on another long hiatus. My original idea for this blog was to record the often random thoughts that go through my head all day while I climb trees. Somehow, it morphed into a tree advice and education column. As much of my time is already spent in these pursuits, I kind of got burned out on blogging.

So here I am, back to share some photos from recent climbs without any yucky education to go with. First, I was working near the lake, where high humidity leads to unusual amounts of ball moss (Tillandsia recurvata). I was climbing a live oak, and what had appeared to be a large cluster of the bryophyte turned out to be a bird's nest. Pretty sneaky! Even in this photo, it's hard to see, but it was really quite well formed and deep. It looked very cozy, although nobody was home. I think the year is over as far as baby birdmaking is concerned.







Another job was more reptilian. First, I was moving across the tree when I looked up to see a big lizard, about a foot long. Usually, I see these as a flash of gray as they disappear into the underbrush or up into the highest canopy, but this guy sat there long enough for me to take a couple of closeups. I then had to take off a couple of twigs a few inches from his nose. It was the second of these that finally were too much for him, and he did, in fact, disappear up the tree.

Later that day, I noticed a small snake (thin, but maybe two feet long) slithering along a branch. He was not as quick as the lizard, but he was quick to move away from me. He slithered out a branch a ways, then, when I followed him with the camera, dripped down into the bushes below, which offered him better camoflage.

And that's a sampling of what you miss if you never climb a tree. I hope to get better about regular postings, even maybe some that might teach you a little bit.

Root Crowns

Most people never get to see what a tree looks like underground. Today we did some root crown excavations so I took a few pictures. This first one shows clearly what can go wrong and why we sometimes excavate.

The tree is about 10 inches in diameter and the width of the hole is about two feet. We blew out the top six inches or so of soil to get a look at the primary trunk flares. When soil gets added around the base of a tree, it loses some of the deepest roots that no longer get enough air and/or water. It responds by sending new roots upward toward the surface. Sometimes a small root crosses over a flare and chokes it off like a noose. The dark line across the center flare in this picture is such a girdling root. We cut it at either end to relieve the pressure, but left it in the groove that had formed around it so as not to damage the bark underneath.

Another problem with added soil is that it traps moisture against the stem of the tree. Roots are well equipped to keep out water they don't want, but stems and branches are not. Trapping moist soil against the bark can lead to decay, disease, or insect infestation. The second picture shows a tree that was about 4 inches too deep. In this case, it wasn't from raising the grade of the lawn, but rather it is a recent transplant that was buried too deep. It may have been the fault of the installer, but just as likely could have been that way in the container. Nurseries tend to add a little soil to the top of the root ball each time they repot, so often container-grown trees are several inches deep before they are ever purchased. The next shot is from the other side of the same tree. You can see a dark line where the soil was before we started at the bottom of the gray bark . The hole is a little deeper than it needs to be because we like to inspect thoroughly for problems when we have the opportunity. When all is finished, we will fill the deepest parts of the hole, leaving the arching trunk flares exposed.The last one shows a tree that has been excavated and had the soil aerated to about 10 feet from the trunk. There are bits of grass still poking through, but it has been pretty dried out and may not survive if we left it like this. The final step is to spread compost over the soil, then top it all off with a three-inch layer of wood chips as mulch. That combination will choke out almost all of the remaining grass. Any stragglers that poke through will be easily pulled out. By creating this buffer between tree and lawn, we avoid weedeater damage and make more water and nutrients available to the tree (grass is a very good competitor).

I'm often asked how far out a tree should be mulched. I always say, some is better than none, and more is better than less. In a forest, there would be little or no grass and everything would be mulch. The closer we can get to that ideal, the better off our trees will be. For more information about mulching, visit the ISA consumer site.

Leaf Rollers

In Austin, it's oak leaf roller season. Every year, live oaks are visited by these small, green caterpillars. Some years, it seems like a plague. This year, I have not seen many yet, but there may still be time.

Most people notice these things when they start dangling from the trees. They will hang by a single strand of web, similar to a spider's web. For those of us who find tiny, green worms really creepy, this can be a very difficult time. Walking to the car or mailbox means dodging worms and webs left and right. Often, after I've been working among them, I feel something tickle me hours later and absentmindedly squash one of the caterpillars onto my fingers. It's not very pleasant, but really it's no big deal for the trees in most cases.

Today I didn't see any caterpillars, but I did see the signs they were around. These photos show how the moth gets its name. On the right is a healthy branch next to one with all the leaves affected. Below is a closeup of some affected leaves. If you pry open those curled leaves, you will find inside either a larva or the remains of a cocoon that one made.

We usually get a few calls every year asking what to do about these critters. In the heavy years, we tend to get a lot of calls. But, except in severe cases, there really isn't much cause for action. The caterpillars eat some of the leaves, and some people get really creeped out, but things quickly run their course and the problem solves itself. The birds feast during heavy years, leading to light infestation the following year.

If a tree is so covered that it seems likely to suffer from the leaf damage, treatment would be the same as for any worm or caterpillar. I recommend spraying with Bt (Bacillus thuringiensis), which is deadly to larvae but pretty harmless otherwise. It still is wise to take care with Bt, since it does not discriminate between nasty larvae and caterpillars of desirable, pollinating moths and butterflies. Stronger pesticides are available, of course, but they would be overdoing things in this case. The Bt will do the job, and if it misses a few, they will be gone soon regardless.

Pecans

The State Tree of Texas, Pecan (Carya illinoensis) trees are among the largest in our area. They make nice shade trees in addition to providing an edible nut. The natives tend to have small, bitter nuts that are mostly scavenged by wildlife. But planting the right cultivar will yield bushels of the things every couple of years once the tree is established.

As an arborist, I have mixed feelings about these trees. Of course, I love a big, nice tree, but working on them is a real challenge. First, their bark comes off in flaky plates. These plates are notorious for grabbing lines and not letting go. To ascend a tall tree, most climbers throw a sack of shot on a light cord through a nice crotch. When the bag comes back down, the climber ties on a rope pulls it into the crotch, then climbs it into the tree. Pecans often thwart this process. The small cord gets caught under a flake of bark and the bag won't drop. It sometimes takes several good throws before one finally returns to the ground.

Once the rope is in, the real work begins. Pecans are brittle trees that tend to sprawl out in every direction. They get really heavy with nuts in the fall. The older ones have often had at least one "tree trimmmer" strip them out at some point, so there is little interior growth and not much branch taper. What this all adds up to is, they often overreach and break large limbs. When a good arborist is at work, almost every Pecan job will include some crown reduction.

Crown reduction is more than just taking out weight, though it often gets called weight reduction. Taking a heavy branch from the inside of the canopy will not help much. If you imagine holding a dumbell, it's a lot easier to hold it close to your body than at arm's length. The same principle applies in trees. Removing interior growth does very little to reduce strain on weak limbs while contributing to weak taper development and exposing the entire crown to more wind stress. A proper crown reduction is better thought of as sail reduction. By shortening the longest limbs, we reduce the surface area that is hit by strong winds. This is the relief the tree really needs.

So, the climber has to get to the ends of branches. That's in a tree known to break easily. Often, it's a tree that has broken already in the past, so there is not always a nice, central tie-in point to allow for easy movement through the tree. The branches tend to be widely spaced, so the climbing is more difficult than in trees where it is possible to step from branch to branch like in a jungle gym. Once there, a climber has to cut branches and drop them 75 feet or more. In a suburban lawn, that's a big opportunity to break something; most branches have to be held until they can be tossed to a safe area.

These are things that get a real climber going. Some climbers are in it for the trees; some are in it for the money (such as it is). But, a few of us do it for the thrills. Pecans are for us. As much as I might complain, I really enjoy doing something that few people can. I get great views and, usually, nice breezes. These early spring jobs don't provide much shade, but in the summertime, I have shelter from the sun, as well. In late October and early November, pruning a pecan means all the nuts you can eat and a bag or two to take home for pie or pralines. And, since they like to grow near lakes and rivers, sometimes we get to see interesting birds and other wildlife.These crested something-or-others (the client told me what they were, but I'm a tree guy, not a birder) hung out all day near our last pecan job. There was also a red-tailed hawk in the area. I enjoyed watching and hearing it on and off for a few days.

I've been sitting on these photos a few weeks now--if anyone is actually following this blog, they may have noticed my long absence (sorry, I got down after that HEB mess). Today, the trees above are probably either covered in catkins, or fully leafed out, or both. I missed out on the shade on this job, but my sunburn is healed and I enjoyed the wide open skies while I was working.



UPDATE: If you've been wondering about the trees I reported on last time, I have learned more. I sent photos to the City Arborist, and he told me there will be penalties for the damage done. Austin has an ordinance requiring a certain number of trees per 'x' parking spaces. Even though the parking lot has been there for decades, they still have to comply with the ordinance. It is only slightly more consolation than before, since the trees are irrevocably damaged, but I hope the penalties will send a message to the property manager that this kind of shoddy work will not be tolerated. As much as I might like to see them paying top dollar for premium work, I will be satisfied knowing that at least they will be motivated to find a reasonably qualified company for future tree work.

Incidentally, the guys did go back to paint their wounds. They painted oaks, elms, and sweetgums. They managed to skip the sycamores. They painted everything they could reach from the ground (more or less) but didn't get the upper canopies. All things considered, this is not a big concern to me. But it's one more piece of evidence that these guys do not know what they are doing.

Hacks!

I've been on an odyssey for the past two days to find out who is responsible for the horrendous tree hacking that went on last week at Hancock Center. This shopping center, at 41st St. and Red River, has a huge parking area with City-required medians planted with trees. A few of the trees have been there for decades and are quite sizable; most were planted a few years ago as part of a major mall overhaul.

Now, I do not expect shopping centers to hire the best arborists in town to maintain their trees. I wish they would, but I know they are going to look for a low bid and focus more on clearances and safety than on proper tree care. But this project hits a new low for the worst in tree care.

I do not believe there is a single industry standard that was not violated on this project. Flush cuts were the norm, but in some cases they went beyond to inexplicably bad cuts. The trees were routinely lifted beyond the industry standard of 1/3 trunk and 2/3 canopy--most are closer to 3/4 trunk and 1/4 canopy. Several crape myrtles were topped, which I've already noted is common, but at least one live oak was topped, as well. The range of flaws in the cuts is staggering--everything from flush to stubs to just random angles. The workers frequently overshot their cuts, resulting in nicks and gashes in the stems of the trees. And, even though they were doing this work at the beginning of oak wilt season, none of the wounds on the oak trees was painted (a basic oak wilt control measure that every arborist and even most hacks know about in Austin).

I saw this damage yesterday when I dropped in to the mall for lunch. Thus began my odyssey. A call to HEB, the magnet grocer at the center, gave me the name of the property manager, Regency Centers, and the person responsible for the account, Korinne Clark. I left her a phone message yesterday, and another this morning. I then called the general switchboard for her office and left a message with a secretary. A little more googling found me Ms. Clark's supervisors, who I e-mailed. I also reported what I had seen and e-mailed some photos to the city arborist.

I was feeling likeRegency was avoiding me, but this afternoon, I finally got a call from Ms. Clark. She told me the work was performed by a Houston company (where she is based), Center Services. She told me they had subbed out the work to someone else. I next tried to find Center Services in Austin (if that's you, sorry for the erroneous phone message--that's what you get for choosing such a generic name, I guess). But then, a little while later, I got a call from the company owner at Center Services. He seemed genuinely upset at the results of this project. He used some of his employees, who had previously worked for a tree service in Houston, and who had "trimmed" some trees in Houston without hearing any complaints (no surprise there--see my earlier post "I don't like Ike"). He vowed never to "trim trees" again, and stick to what he knows.

I suppose this is a small victory, but, sadly, the damage to the trees at Hancock can't be undone. The Center Services guy said he sent his boys back to paint the oak wounds. It's too late to make any difference (by now, the tree has sealed off the injured vascular tissue), but at least it won't send the wrong message to the public that painting is unnecessary. I'll be curious to see if they can correctly identify the oaks among all the trees thay damaged. The Center Services guy offered to do any other chemical treatments to correct the damage. But there is no such remediation. Trees do not work like animals. They have no immune system, they cannot heal wounds, and they cannot regenerate lost tissue. They can only limit the spread of decay through various chemical and physical barriers (CODIT). Unfortunately, the numerous flush cuts made on this project removed the branch collars, which form the strongest defense the tree has against spread of decay (wall 4). Some of these trees will probably die due to loss of energy-generating tissue. The ones that survive will probably begin to fall apart in a decade or two, due to the fact that they were not able to quickly seal off the outside exposure represented by these wounds. The mall will lose some property value (trees provideup to ten percent higher property values--some estimates go up to twenty percent), will have to replace the asphalt surface sooner (the shade of trees protects pavement against degradation), and will likely deal with claims from shoppers whose cars are damaged by falling branches or whole trees. The City will lose some money because it has to treat more storm water (trees absorb runoff and clean water), will be more likely to face federal management of vehicle emissions (trees clean pollution from the air [link requires Adobe Acrobat Reader], delaying such mandates), and will be hotter (trees reduce the heat island effect). And, though the effect on this one site is probably pretty small, the increased need for air conditioning may contribute to the City's need for new power production facilities (Austin owns its own electric utility).

I reported all of this to the City Arborist, but I suspect there is nothing he can do. City ordinances require these median trees to be installed during construction and maintained for two years, but I 'm pretty sure two years have passed. Ordinances also protect trees at least 19 inches in diameter at breast height, but I don't think any of the affected trees is that large (maybe one or two are). So all we can do is continue to educate people about the consequences of bad tree work. Tell your friends.

Lichen

After ball moss, the most frequent question we hear that is not really a problem relates to lichen. Lichen often grows on trees, but also turns up on rocks or pretty much anything else where conditions are right. Lichens are a symbiotic organism made of algae and fungi. The alga makes energy through photosynthesis, while the fungus provides water and minerals from the substrate. The most common lichen in our area are thin, gray sheets. This is what people often see low to the ground, especially in deer-prone areas, where the protruding parts may become snacks for the local fauna.

But when you get higher in the canopy, you see all kinds of sizes, shapes, and colors. Well, several kinds. When you prune a tree, you have a lot of time to sit and look at the small stuff.


Sometimes you see splash cups, which help to distribute spores.


In the end, I'm more of an arborist than a biologist, so I just like to look at the pretty forms.

Today, it also happens to be time for redbuds to start blooming. Unfortunately, blogger doesn't seem to like so many pictures. Sorry for the random layout.