Question
I have a beautifully shaped crape myrtle in my front yard that has the type of fungi/moss, the type that attaches itself to all the limbs of the tree. It's a grey/greenish color (kind of looks like ocean coral). I was told that I could use copper to rid it from the tree. I bought some yesterday and don't know how I sould apply it, to every limb or to the root system to be absorbed.  I don't want to loose this tree!! Please help, I hope that I have explained everything properly.

Thank you ever so much,

Clara Batten

Answer
Sounds like lichens. Lichens are an example of a symbiotic relationship between algae and certain fungi. They are capable of producing their own food. The algae associated with the fungus is a green or blue-green alga. There are three forms of lichens based on growth patterns. Crustose are species that are closely pressed against the surface of the limb or trunk of dead or live trees. Foliose forms are leaf like or prostrate but are also tightly attached to the tree. Fruticose forms are bush like, erect or hanging. Although lichens are found in most areas  they are most noticeable in areas that have extended periods of high humidity.

The effect of lichens on a tree are only slightly detrimental. The plants are epiphytes. That is they derive their nutrients from the air and not from the plant on which they are growing. Although they are not parasitized, literature reports suggest that lichens do have a slight negative effect. The main concern is that lichens give a tree an unkept appearance. Presence of lichens also is a good indicator of a thin tree canopy. This often leads homeowners to conclude that lichens are the cause and not the effect of thin foliage. The best control for lichens is maintain the tree in good condition. This will insure a dense canopy which will shade the limbs and reduce photosynthesis. Without photosynthesis, lichens are not able to manufacture food needed for growth and development.

Copper containing fungicides are suggested as possible controls for lichens. Applications of Kocide DF for the control of ball moss, have been observed to control lichens for a short period of time. Currently copper fungicides are not approved for lichen control. Because of their limited affect on a plant, chemical control is not suggested. It will be applied to the limbs and the trunk. It is best applied before the leaves bud out in the spring. Same is true fro the baking soda use. No need to apply to the soil or roots.

The baking soda recommendation I have heard of is 40 pounds of baking soda per 100 gallons which comes to 0.4 lb of baking soda to 1 gal of water. But I would not do anything about the lichens but I would fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. this will increase the overall health of the tree.