Whether you notice it in the fall and spring or it’s year-round, moss growing on trees can look quaint or pastoral and give your home or yard a mature and majestic appearance. However, the moss growth could hide damage to the tree and could even spread to your home and other parts of the yard, which could then cause damage to your home. It could even take over your lawn!
But before you panic, here are four essential questions (and their answers!) about maintaining your trees when you find moss. Once you know what moss does and doesn’t like, figuring out how to influence it is all you need to do.
What should I look for when I inspect my trees for moss?
Moss, lichen, and algae all fall under this category commonly referred to as just “moss.” These plants come in many variations, from Spanish moss (which hangs down off the branches of a tree) to lichens, which look more like crusty patches or what might remind you of fluffy troll doll hair. All of these plants prefer cool, wet, rainy conditions—easy to come by in the Pacific Northwest. They are versatile and can grow almost anywhere too—on trees, rocks, wood, clay, or the ground. Moss is a non-vascular plant, meaning that it has no roots and will cling to anything that sits still long enough. Remember the proverb “a rolling stone gathers no moss”?
Mosses also love dark areas, so make sure to prune back your trees seasonally and check your roof often if your overhanging tree branches tend to grow moss. If you let more light hit the trunk and major branches, you’ll see less moss because their favorite dark conditions will have been compromised.
Is moss harmful to the tree itself?
Nope. Moss, lichen, and algae all live on the tree and receive their nutrients from the sunlight and the water around them. Unlike English ivy, mosses aren’t parasitic, and unlike dry rot, mosses don’t eat into bark or exposed wood.
That being said, if a tree is covered in moss, it’s most likely that the tree is an older one that can’t fight off the encroaching moss, and it’s a good indicator that something else might be wrong with that tree. If you notice that a tree isn’t doing well and has moss growing on it, the moss isn’t causing the problem. Rather, the moss is just a symptom. Once you fix that other problem, it might even be easier to remove the moss and prevent it from coming back.
Moss can also hide damage or signs of disease that would otherwise be apparent. What is harmful to the tree would be the added weight of the moss, which is water heavy. Imagine if a windstorm came up and started tossing your tree around. With the extra weight, a tree could easily overbalance, and branches could be torn or broken off and cause some damage to itself and anything around it (such as your house!).
Can moss be removed?
Yes, and as an added bonus, it’s fairly easy to do. Moss in particular tends to grow in thick mats that you can pick or peel off of the branch or trunk of your tree. Make sure to wear work gloves. If it’s stubborn, you can use a bristle brush as well.
If the project is bigger than you think you can handle, you can also try power washing. Make sure to wear eye protection and stand back about five feet from the tree. You don’t want to damage the tree you’re trying to save.
Of course, Mr. Tree can help as well. Contact us to tell us all about your mossy trees.
What can I do to prevent future moss growth on my trees?
As referenced before, trimming your trees so that enough sunlight gets through is a good way to interrupt moss’s favorite growing conditions. Also, make sure to check out your lawn. Are there any regular standing puddles of water that appear during or after watering? You can aerate your lawn to disperse the puddles—that might be the source of excess moisture that moss likes best. Take a look as well at how shady your yard is. You don’t need to water a shady lawn as often as you do a sunny lawn.
If that isn’t a contributing factor, maybe check out your watering habits. Even in the middle of a hot, dry summer, it’s usually best to water deeply two or three times a week, rather than every day. Waiting between watering days ensures that the soil has enough time to dry out. This less frequent watering also helps promote strong root growth for trees, which will keep them robust. A mature tree will need an inch of water per week.
Young or newly planted trees shouldn’t have any problems with moss. Their roots haven’t spread out yet from the root ball either, so you can water the base of the tree until the soil is wet but not soggy. Make sure to note, though, that for older, more-established trees, watering only in this area could encourage disease and rotting. Instead, move farther out, past the canopy of the tree to the drip line, or where rain would drip off the leaves. This is where it’s best to water because the roots extend at least that far. Water until you start to see runoff; this means the soil is saturated. The water in the soil displaces the air, and a tree has to breathe too.
Once you’re sure the tree has received enough water, check back in a couple of days to see how the soil looks.
Make sure that you don’t have moss growing in the lawn as well. If you aren’t able to cut back or completely eliminate moss on a tree, it may be because the moss is still present in other places in the yard. It’s like trying to recover from your own flu while your family members all have it too.
And, of course, our experts are here to serve you! Contact us today to schedule a service and to ask any questions you might have—about mossy trees or anything else!