"Doctoring" Your Trees

Children hate to get shots, and most adults I know are pretty squeamish about needles, too. But, shots can prevent illness through vaccination, or cure illness already present through the injection of antibiotics. Now, the methods previously reserved for your arm, and other parts of your anatomy, are available for the trees in your yard.

Systemic injection is simply a procedure using a needle-like implement to put chemicals directly inside a plant's tissue. Still considered a new system of treatment for trees, much research has been done lately to determine the best area to insert the "needles," the best chemicals to use, the speed of movement of the chemicals as they travel trough the plant, and their eventual location in the plant.

I'm not certain who told me the story, but tests were performed on redwood trees in California, several hundred feet tall. A colored dye was injected and the tree experts were stationed at the top of the tree to determine how quickly the dye would travel from the point of injection to the top. As the timer was started (immediately following the injection) someone from the top yelled, 'It's here!' - indicating just how quickly fluids move up through a plant, and later down into the root zone.

Systemic injection is rapidly gaining importance because of the potential of saving trees from deadly infestations of bark beetles, which carry Dutch Elm and other diseases. Literally hundreds of thousands of trees have died from this fungus that causes clogging in the vascular system in a tree; not unlike hardening of the arteries in people. Dutch Elm Disease is still not totally curable, but research using systemic injection is being done by several organizations across the country.

Several other health problems of trees are treatable through use of systemic injection. For example, chlorosis, a condition usually caused by lack of iron, can be treated. Yellowed leaves, stunted leaf growth and brown edges usually characterize chlorosis. In an alkaline soil, the iron may be present, but unusable to the tree. Through systemic injection, small amounts of iron can be injected into the tree and the plant can be saved.

The process is becoming more refined. Some damage to the trunk will occur in the process of injection because typically holes are drilled in several locations in order to perform the procedure (and you thought a tetanus shot was a problem!) Through study, the best area to drill these holes seems to be at the buttress root flair where the tree trunk gets thicker then narrows just above the roots, before they go into the ground.

These holes can leave the tree open to possible infection or infestation, since the bark is not like skin - it won't "heal," it simply closes over the injury. While this is still a concern to some tree growers, industry experts believe that insecticides, fungicides, fertilizer and trace elements, such as iron, can be introduced safely to the plant, preventing and curing more ills than the procedure causes.

A lot has been done so far with the injection of insecticides, too. In my opinion, a lot more will be done as we find ways to control insects without having to add chemicals to the air we breathe, which occurs when spraying into tree tops, etc.,

Arborists are generally the only ones who should use the chemicals found in systemic injection since many have dermal toxicity - poisonous through your skin. As professionals learn more about these products and how to use them, I think it is likely that more insecticides and fertilizers, etc., will come into general use. For now, you should bring in a professional since it's frequently difficult to determine the cause of any given problem with the trees in your yard.

Let the real tree "doctors" give your trees their "shots." But realize that no one will get a lollipop.