Getting to the root of tree problems
BY THERESA FRIDAY Extension Horticulture Agent Santa Rosa County

Trees are an indispensable part of the landscape. They give a home, street, or commercial site individuality, beauty, and tranquility. Because of their long life, trees give the surroundings a sense of permanence and stability. During the hot, humid summer along the Gulf Coast, some trees will develop disorders or conditions that concern homeowners.

Many questions on trees are about problems with the leaves. This is no surprise because the hot summer days along with the high humidity provide optimal conditions for insects, fungus, bacteria and mold to thrive. We see these organisms living on the leaves often by noticing dead spots or a crumpled look to the leaf.

Often these problems, while not good for the trees, are no more serious for the trees than dandruff and warts are to us. Most of the time, while it is nice to find out what it is, our recommendation is to leave the problem alone.

Another common problem that we see this time of year is squirrel damage. Squirrels, if you haven't noticed, are doing well for themselves and are quite abundant in our urban environments. They survive by consuming tree seeds and eating fungus, but they also will chew off tree bark and lick the sap from these injured areas.

They do this most frequently on thin barked trees. We get many calls about this on Japanese maple, but I have also found squirrel damage on crepe myrtles and oaks as well. It is recognized by the bark having been chewed off and if you look closely, you will see actual teeth marks. The only thing that seems to work is to wrap a fairly small holed fencing wire around the trunk and/or branches of the tree.

Sometimes in our attempt to have a weed-free lawn, we over use weed killers like weed and feed. This is especially common in shady areas where grass might not be doing well. Some of these weed killers which are applied directly to the grass kill dicot plants and not monocots (grass is a monocot).

Dicots include not only many of the weeds that we intend to kill but also large trees like oaks and dogwoods. When heavily used, this weed killer can weaken a tree, causing thinning of the crown. It's best to avoid applying weed killers within the root zone of our woody plants. To help avoid this, establish large mulch beds in shady areas under trees where grass doesn't grow well.

Soil compaction is probably the worst problem for our trees and other plants in our urban environments. Roots need to take in oxygen and release carbon dioxide. In compacted soil, sufficient air can't be exchanged so the soil gets too much carbon

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dioxide in the soil pores instead of oxygen. This poor exchange leads to poor root growth and thus poor tree growth.

To improve soil aeration, use mulch to protect the area under the tree from soil compaction. Also, keep vehicle traffic off areas intended for growing plants.

I am also beginning to see signs of an interesting insect called Psocids. Psocids (SOsids) cause much alarm but like many insects are harmless to the tree. These tiny insects (less than 3/16 inch long) will form silky webbing over the bark of a tree.

Sometimes their webbing covers a small area and sometimes the webbing will cover most of a tree. Under this webbing, these tiny insects consume fungi, lichen, pollen and other organic material that is on bark. Once they have eaten everything, they leave the tree unharmed. The lesson for us is that not all things on the tree are bad for the tree.

Theresa Friday is the Residential Horticulture Extension Agent for Santa Rosa County. The use of trade names, if used in this article, is solely for the purpose of providing specific information. It is not a guarantee, warranty, or endorsement of the product name(s) and does not signify that they are approved to the exclusion of others.

For additional information about all of the county extension services and other articles of interest go to: http://www.santarosa. fl.gov/extension