"Demossing": Ripoff or Responsible?

“De-Mossing”: Rip-off or Responsible Tree Care Practice?

Gene Basler

What’s the story with ball moss anyway? Look at all that dead wood—isn’t the ball moss killing my trees? What can you DO about my ball moss? Here in South Central Texas, we arborists hear such questions nearly every day. While everybody seems to have a different answer, you can be sure there’s a price quote for “de-mossing” in there somewhere. De-mossing is the practice of climbing trees and physically removing the ball moss. It has become so common that hardly anyone questions it. But when we remind ourselves that tree health is our real objective, we have to ask, is de-mossing really a responsible practice?

The practice should really be called “defoliating”, because that’s what really happens in a de-mossing operation. It doesn’t matter which “expert” you hire to do the work. The result is always the same: the trees end up with 30-60% of their foliage removed. Have you ever seen a tree or yard full of trees that have been “cleaned up”, i.e. just a little bit of foliage remaining in the upper ¼ of the crown? That’s de-mossing. The ball moss may be gone; the dead wood may even be gone, but then again so is half or more of the foliage!

This type of pruning is a net loss for the tree, for the key to a tree’s health and longevity is its leaf population. The three main principles of tree preservation are 1) leaf population, 2) leaf population, and 3) leaf population! The more leaves in a tree’s crown, the healthier the tree, and the less likely it is to be susceptible to damage from insects, diseases and—worst of all—humans. As for the ball moss, what harm is a moderate ball moss population? No sweat at all to a healthy tree.

Remember, ball moss, Tillandsia recurvata, is an epiphyte, cousin to such plants as the tropical orchid and the staghorn fern. Epiphytes derive their nutrient and moisture needs from the air; therefore they are not parasites, and they do not harm the trees.

So why all the dead wood? Ball moss prefers to grow in the shade, and that also happens to be where the majority of a tree's dead branches are found. Since the balls amass on the dead branches, they belie the myth that the ball moss caused the dead branches to die.

Now, sometimes a ball moss population does become so dense that it can inhibit the tree's foliage output. This almost always occurs on a declining tree that has other, more pressing health concerns. Spraying with sodium bicarbonate might be called for in these situations, but even then it would be part of a comprehensive plan to get the tree’s health and leaf population back to normal. (When properly applied, sodium bicarbonate desiccates the ball moss, and it dies on the tree. Over time the elements cause the dead ball moss to fall from the trees. The results can be disappointing if the customer doesn’t stick with the treatments for at least three consecutive years. Moreover, spraying without pruning merely exposes the dead wood in the tree.)

Our approach to ball moss management is quite different from commonly accepted practices, and is predicated on 2 important points. The first: Leave the foliage intact! If that means leaving a moderate ball moss population intact as well, then so be it. The second: properly maintained trees tend to self-manage their ball moss populations.

Here’s our unique Ball Moss Management Plan in a nutshell:

1. Remove all dead wood 1 inch diameter and greater. Leave live foliage intact¹! A majority of the ball moss will come out with the dead wood: the rest of the ball moss will be left alone.
2. Place the trees on a simple Plant Health Care program². Healthy trees tend to produce fewer dead branches and to have less ball moss growing in their crowns.
3. If the ball moss is still heavy, then spraying with sodium bicarbonate may be called for.

Gene Basler is an ISA Board-Certified Master Arborist with the Bartlett Tree Expert Company. For more information about the services we provide, please call Bartlett Tree Experts at 210-655-4670.

1 In some cases live foliage may be pruned for house clearance, weight/hazard reduction and species separation. Light penetration is a poor reason to prune live foliage from a native Texas shade tree. See article on Light Penetration.

2 Responsible Plant Health Care includes soil management and pest management. Nutrients are applied to the soil based on the results of a soil analysis, and damaging pests are suppressed using the safest means available. 

Please feel free to leave a comment or send an email. If you're looking for a TCIA Accredited Houston Tree Service or Certified Arborist, call the company I've worked for since 2002, Bartlett Tree Experts, at 713-692-6371. This is my personal blog--it is not affiliated with Bartlett Tree Experts.