They absorb the air from their environment, which includes the nutrients it needs to survive, as well as any harmful toxins that may be in the air. Sometimes it appears that lichen is hurting your tree because it grows at the same time your tree is declining. There are over 20,000 different kinds, and they come in a variety of colors and shapes. Change ), You are commenting using your Google account. How Drought Affects Fall Leaf Color in Colorado Trees →. Exactly! Here in Colorado, there are hundreds of lichen species that exist in practically every environment imaginable, including some with interesting common names, such as pale-footed horsehair lichen, lustrous camouflage lichen, salty rock tripe, and veinless pelt (although those don’t generally grow on trees). Change ), You are commenting using your Facebook account. Surprisingly, lichen can actually be of benefit. It gets all of the nutrients it needs from rain and the surrounding air. The presence of abundant lichens on a tree could indicate that it’s in decline, with a less dense leaf covering than it should normally have. They may not be harmful to the tree, but it is true that they look bad. If so, don’t blame the lichens, but give the tree better care. Change ), You are commenting using your Twitter account. I love the way lichens decorate tree bark, a different spin on winter interest. Because lichen is self-sustaining, it does not need to take any nutrients from the tree that it is on, and therefore is not harming the tree. Think of their presence as a sign to visitors that nature is welcome in your garden. Lichens have just settled in because there is less leaf coverage on those branches and they need sunlight in order to grow. Lichens grow on the surface of your tree, and do not penetrate any tissue. When trees lose their leaves in the fall, you sometimes discover crusty or fibrous grayish or milky green growths on the branches and trunks of your trees. Lichen loves sunlight and moisture, so it is often found in sunny, wet spots. Rub gently, being careful not to damage the bark or dormant buds. It gets all of the nutrients it needs from rain and the surrounding air. In no way are tree lichens harmful to the bark on which they grow. They are strictly epiphytes, that is, organisms attached to the outside of the bark. Having lichens on your tree is very fortunate as it means the air you are breathing is clean! It’s a natural air quality indicator, as it absorbs everything in the environment around it, but only thrives when the air quality is clean. The belief that lichens kill tree branches is an old myth. Lichen is also found on rocks, the ground, even tombstones and statues. Many birds—including hummingbirds!—use lichens to build their nests. But the reality is, lichen is an opportunistic organism just looking for a surface to grow on, and unhealthy trees happen to be a good option. Lichens absorb nitrogen, oxygen, and carbon from the air. And while ghostly gray and muddy green are their main colors, they can come in all sorts of shades, even bright oranges, yellows, yes, even pink! Photo: Neil Sperry, theeagle.com. They are not parasites (which, by definition, harm their host) and seek nothing from the tree other than a support on which to grow. Some lichens (but not all!) When it rains, some of this nitrogen trickles down to the roots of the host tree, helping it grow better. It just needs a place to grow. So many people believe that lichens are causing the distress in the trees that are overloaded with them. Well, there’s good news and bad news. You could try fertilizing it modestly and watering it in times of drought. Also some animals feed on lichens, including reindeer and caribou (caribou moss, the main winter food of caribou, is actually a lichen: Cladina spp. Lichen also converts carbon dioxide to oxygen and absorbs any pollutants that are in the area. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. After all, lichens aren’t fungus, are they? Covering the Foothills & Mountains West of Denver. are even edible! It’s not burrowing into your tree, but rather staying on the surface of the bark. they aren’t the problem. They are found on every continent, from humid forests to frozen areas and desert sands. Animals are fond of lichen as well – deer use it as a food source, it provides a protective cover for some beneficial insects, and birds like hummingbirds use it in their nests. It can survive when plants can’t and can grow on rough surfaces like rocks or old fences. And finally, lichens need to have a substrate on which to live. Finally, indigenous peoples all around the world use lichens in medicinal treatments and in preparing dyes. Lichen often grows on trees that are already in decline, rather than on healthy trees. If lichens start to grow on your trees, that’s good news: a sign that the air is fairly pure! Also, lichens have the capacity to absorb nitrogen directly from the air. In fact, lichens are moving back into cities after decades of absence as air quality improves compared to what it was in the 1970s and 1980s, back when leaded gas and industry chimneys belching toxic smoke were the norm. Are lichens harmful to your trees? First of all, they make interesting pollution indicators, as they won’t grow in polluted air. They are strictly epiphytes, that is, organisms attached to the outside of the bark. Lichen is self-sustaining – it doesn’t take any nutrients from the tree that it’s on and therefore doesn’t harm the tree (although some people consider it unsightly). In fact, scientists use lichen as a measure of air quality in different areas. ), for clothing, decoration, and even for antibiotic uses – you might find it as an ingredient in your deodorant or toothpaste, for example! Or if there is a drainage problem, fix that. Adding to the confusion, “reindeer moss” or “caribou moss” is actually a lichen, and is a popular food source for caribou. If however, you really don’t like the look of lichen, the best method is prevention. The good news is that the lichen is not harming your tree. That is why today we bring you this guide so you can learn how to get rid of lichen on trees. Over 6% of the earth’s surface is estimated to be covered by lichens. © 2020 LAM Tree Service, Inc. All rights reserved. But while lichens may warn of a problem. Lichen is usually the first type of organism to appear after a natural disaster, such as a fire. Those grayish-green patches, usually one to three inches in diameter, are not feeding on your trees. These are not fungus, but lichens: composite, symbiotic organisms formed by the association of algae or cyanobacteria and a filamentous fungus. The bad news is that if your tree is suddenly sporting a spot of lichen, your tree is probably already in decline. And sometimes trees just die and nothing can be done to save them. Lichen is unusual in that it is a symbiotic relationship between a fungus and an alga or a cyanobacterium, plus usually one other organism thrown in for good measure. Other critters, like frogs, enjoy it as a snack. In fact, you’re likely to injure the bark by trying to remove the lichen, ultimately causing damage to the tree and providing entryways for diseases and pests. ( Log Out /  If you have noticed that lichen has settled on the tops of your trees, then this is the ideal blog for you. ( Log Out /  This could be a tree, rock, soil, old cars, or just about any inanimate object.