Ball moss and lichen control – Do or don't … that is the question

As I promised on last weekend’s GardenLine show, here’s an update on all things lichen and ball moss.

By the end, you’ll know if you want to control either or both. You may also decide to leave both of them alone.

I’m going to give you my opinion and the opinions of other experts. Then, you can do whatever you darn well please.

First, some definitions:

Ball moss is an epiphytic plant, meaning it derives its nutrition from the air, not the tree. So, that’s why tree experts say it doesn’t have a negative effect on a tree. I agree with that, but in my opinion, it should be controlled now so it doesn’t get out of hand and become downright ugly. I also believe an over-abundance is detrimental the overall health of the tree in the long run.

Lichens on trees are unique. This is the green, blue or gray, feathery or wavy growth on the bark. They are actually formed from a symbiotic relationship between two organisms — fungus and algae. The fungus grows on the tree and collects moisture, which the algae needs. The algae, in return, creates food from the energy of the sun, which feeds the fungus. Lichens on bark are completely harmless to the tree. It’s often thought to be worse in areas where there’s a lack of air circulation. The rhizines (similar to roots) allow them to attach to the tree but do not go deep enough to actually harm the tree. To learn more, see www.gardeningknowhow.com.

Lichens can also be found on rocks and other inorganic objects, demonstrating that they receive no nutrients from a host tree. It’s similar to mistletoe. Although found in most of Texas, lichens are more often found in humid areas, such as along the Gulf Coast. Often, they are believed to indicate poor tree vigor. Lichens require a certain amount of sunlight, so if a tree is healthy with dense foliage, lichens don’t develop on them. When trees are weak, though, lichens can proliferate and cause concern. It’s very important that trees be maintained to insure maximum foliage, and that means following the Deep-root Feeding tip sheet.

Some researchers say there is no specific control for lichen, but let’s not play dumb here. It’s a fungus and algae combo.Almost any fungicide will have an effect.

So, with all that said, let’s examine what stays, what goes, what we treat and what we don’t treat. No bloviating research here … just my points and my opinions.

Lichen –

• It’s rarely deadly to any tree and easily treatable if you just don’t like the look
• It’s a fungus and algae combination, and it’s not robbing the tree of any nutrients
• It is, however, caused by a lack of air circulation in the area
• It is easy to control with copper fungicides, systemic Banner-based (or PPZ-based) fungicides or Consan 20.
• If left alone, after 20 years or more it can have a suffocating effect on tree limbs.
• Prune out and destroy any heavily infested branches, especially if they appear dead.
• If you like it, leave it alone; if you don’t like it, control with a fungicide quickly.

Ball Moss –

• This is the greyish, green, hairy, spiny, sea urchin-like tuft of air plant, also commonly known as an epiphyte.
• It alone is not what’s making a tree’s health decline.
• But an unhealthy tree that starts to rapidly produce ball moss will be suffocated quicker than one with untreated lichens.
• It’s very easy to get rid of in its earliest of stages by pulling ‘em off
• Blasting them off with water pressure is amazingly easy.
• Treating with a copper fungicide or a systemic Banner-based fungicide can work, too.
• Once a tree is overwhelmed by ball moss, I don’t believe fighting it is worth the effort or money. So, let’s catch it in the earliest of stages
• The best time to apply fungicides is just after early infestations are removed, because the freshly exposed areas will be coated before new epiphytes can take hold.
• Prune and destroy any heavily infested branches, especially if they appear dead.
• If you’ve done everything you can to remove the epiphyte, focus next on deep-root watering and feeding to help make the tree generally healthier.

Now, let’s dive deeper into what happens when fungicides are used to control ball moss, because you’re going to need a lot of patience to experience complete results. When using the copper- or PPZ-based formulas, it is important that all the moss be saturated with the spray. To be effective, applications must be made before or during the rainy season, usually mid-February to early June. This insures that the fungicide is on the moss and waiting to be absorbed with the next spring rain. Ball moss treated with copper-based fungicides will die over a six- to 12-month period but will remain in the tree because of its "hold fasts." In most cases, it will take 18 months for these attachments to decay sufficiently so the moss drops from the tree. That’s why I like physically removing it first.

By the way, many die-hard organic gardeners believe in a treatment of baking soda and water in lieu of chemical fungicides. You can certainly give it a try, but there is no research to back up its effectiveness. And even if mixed perfectly and applied correctly, it can take over 12 months to produce results. I have personally tried it and was not impressed. But I did get results with copper- and Banner (PPZ)-based treatments in under a year, and it lasted for years. I also got those trees on a deep-root feeding program right away.

The points above haven’t changed in 30 years. But, in the past five years, many have started to argue that “you don’t need to treat for ball moss, it’s perfectly fine!” Why? Some articles - one from Texas A&M’s Forest Service and another flurry of stories about how to use “Ball Moss for Making Christmas Wreaths.” Combined with some readers’ failure to study the entire articles, taking out only what they wanted, and here we are in a time when some people want to “save the ball moss.” Ugh!

I hope you’ll take my advice, even if you don’t like it, if you want to give every tree its best chance to live longer. I can assure you too much of either lichen or ball moss is never a good thing, no matter what some researchers and newspaper articles have recently said about their effect on the overall health of trees.

At the very least, if you’re like me, you know that (leaving endemic health arguments out) too much of either of these on any tree just doesn’t look good. For that reason alone, I will always employ some control measures.

In the end, lichen or ball moss on a tree or shrub IS NOT KILLING IT! But if it’s loaded with either, it has many more systemic issues than just the ball moss or lichen. An overabundance of either will suffocate it over time and not help it get better.

In my opinion - and that’s all this is - keep the lichen but remove and kill the ball moss. Thud! (Drops the mic and walks away.)

PHOTOS: Getty Images and Randy Lemmon