Tillandsia recurvata - "ball moss"

Tillandsia recurvata – “ball moss”

The debate over ball moss has stressed marriages, destroyed friendships, and caused heated debates between professionals. Many observers are absolutely certain they have seen ball moss kill branches and trees. Others point to the ball moss growing on an outside wire and swear it can do no harm. Experts seem to be split in their opinions about this small frizzy bromeliad.

Appropriately, ball moss is not a moss but a true plant that flowers and sets seeds; so even the name is wrong. Unfortunately, the flower is not showy and the small, fluffy seed readily blows everywhere. And seed is produced twice a year, spring and fall.

Ball moss absorbs water and nutrients from the atmosphere and only takes light and space from the tree. The pseudo-roots that tightly hold the plant to a branch do not absorb water or nutrients.

Ball moss thrives in the interior areas of a tree on branches that receive limited light. The tree discards these inefficient branches. No amount of “scientific ” explanation will convince most observers of these dying branches that ball moss was not involved in their death.

So why the heated debate over a plant that does so little harm? Ball moss is ugly. It detracts from the appearance of many of our most beautiful shade and ornamental trees. The difference between a majestic Live Oak heavily infested with ball moss and one without is so striking that the debate should end here. And deciduous trees like our Cedar Elm or Crape Myrtle can be especially unattractive when their leaves are not present to hide the Ball Moss in the winter.

Good pruning that removes deadwood and opens the outer canopy removes most ball moss and will deter the establishment of new plants. Unfortunately, most of the pruning done in this area to remove ball moss is harmful to your tree. When every branch with ball moss is removed leaving only a few green leaves at the end of a branch, your tree has been harmed. This improper, inexpensive pruning is responsible for the decline of many trees. Your tree is better off with the ball moss.

If you are patient, ball moss can be suppressed with an annual application of a copper fungicide, or baking soda or potassium bicarbonate. Dead ball moss may hang on the tree several years after it has been killed, but it is much less expensive to spray than to pick or prune.

Ball moss is a weed and removing it from your tree is a personal decision. If you can tolerate the ugly, it will do little harm to your tree. If you want more attractive trees, ball moss must be managed. Your trees will be a little more vigorous without ball moss and they will be much more beautiful.

David Vaughan
San Antonio, Texas