Question
We have 4 huge pecan trees covered in moss.  I believe the moss is killing the trees but my husband says moss will not kill the trees.  Now the moss is attacking my dogwood and other plants in the yard.  What can we do to stop the spread and try to de-moss the pecan trees.  Thanks for you information.

Answer
Sounds like Spanish moss. see picture. http://oak.cats.ohiou.edu/~cookt/images/travel/spanish_moss.jpg

Spanish-moss, also called Florida moss, long moss, or graybeard, is not a true moss. It is an epiphytic plant, which grows on another plant, but does not rely on the host plant for nutrients; epiphytes make their own food.

They are sometimes referred to as air plants because most have aerial roots; however, Spanish-moss does not have any roots. It uses its long, thin, scaly stems to wrap around the host tree and hang down from the branches. The leaves are covered with cup-like, permeable scales that 'catch' moisture and nutrients from the air and from pockets on the surface of the host. This water-trapping ability allows Spanish-moss to withstand long dry periods. In extreme dry spells, the plant becomes dormant until moisture returns.

While the plant is not parasitic, it can sometimes damage the host tree by over-shading the leaves, thus reducing photosynthesis, or by weighing down and breaking the branches.

It is usually not necessary to control, this moss but it can be if needed.

The following materials are licensed for control of Spanish moss and/or ball moss: TC Tribasic Copper Sulphate, Blue Shield, Basic Copper 53, Micro Flo Basic Copper 53, Micro Flo Copper 3 FL.
The mixture will be printed on the container that you buy. It may not say Spanish moss but use the rate for ball moss.

It should be noted that there is evidence that copper-based herbicides and fungicides may cause damage to tender growth on trees. I would spray before the leaves bud out or wait until about mid summer when the leaves are not tender. As with all herbicides, when using these materials read and follow label directions carefully.

Hand removal of Spanish moss is possible and can be done successfully on small trees by standing on a ladder or using a pole.  The procedure is labor intensive and costly. Homeowners would be well advised to consider the ecological benefits of Spanish moss and let the plant grow unless heavy infestation is endangering the health of the tree through reduced light.

Baking soda has been shown effective for ball moss control at the rate of 40 pounds of baking soda per 100 gallons of water, Mr. Arm & Hammer has not put it on the label SO WE CAN'T RECOMMEND IT! However, if it is used, it should be applied exactly as the herbicides.