Why does lichen grow on trees

Lichen will grow on both healthy, vigorous trees and on older or declining trees. The health of a tree is not related to the appearance of lichen , although many people think lichens damage trees and associate lichen growth with a stressed or declining tree. An older, declining tree may have a sparser crown or leaf and branch dieback, which means an increase in sunlight that reaches branch and trunk bark where lichen grows. An older tree may also have more brittle and fissured bark which offers more places for lichen to attach to.

Plus, an old tree may have stopped exfoliating its bark. Another thing to remember is the slow rate at which lichen grows. If you absolutely must remove lichen, spray your branches with a gentle soapy solution. After wetting the lichen, you can use a natural-bristle scrub brush and gently exfoliate the lichen off. You can wash off the residue with a stream of water from your garden hose. If your tree is in good health, you can prune off branches that have more lichen than is to your liking.

Learn more about types of pruning for your trees. This could include:. Since lichens need a lot of sunlight to thrive, a full-leafed and shady tree crown may be the best revenge. See how trees in Connecticut benefit from supplemental fertilization. In addition to it being an indicator of healthy air quality, lichen is a food source : animals, including squirrels and voles, will eat it; deer will gnaw at it in the winter, and some indigenous tribes in what is now New England would eat it as well when food was scarce.

Birds include lichen as nest-building insulation. There is also a long history of humans using lichen. For centuries, lichens have been used for textile dyes. In the U. These same extracts from lichen that have anti-bacterial properties are found today in toothpaste and deodorants. You may have lichen on you right now!

However, we can evaluate and diagnose what is going on and give you a comprehensive treatment plan. Things change quickly in CT when it comes to pests, weather events, and other things affecting your trees and landscape. Stay in the know with our monthly newsletter. No spam - we promise! In return, the algae creates a byproduct that the fungus feeds off of. So the fungus provides the habitat and the algae provides the food. There are a few mediums where lichens are able to grow.

It is dependent upon where the fungus feels most at home. They can grow on trees as well as bricks, walls, rocks, roofs, and even on soil. Lichens grow on trees simply because the tree provides the fungus a good habitat on which to grow. The fungus sinks very shallow roots that grab onto the surface of whatever it is they happen to be attached to.

This is why so many different places can be home to a lichen. Lichens are not harmful to trees what-so-ever, but some do consider them to be unsightly. 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.

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. Lichen is also found on rocks, the ground, even tombstones and statues. It just needs a place to grow. Lichen is not a plant, so it does not have roots. It gets all of the nutrients it needs from rain and the surrounding air.

Lichen is usually the first type of organism to appear after a natural disaster, such as a fire. The good news is that the lichen is not harming your tree. The bad news is that if your tree is suddenly sporting a spot of lichen, your tree is probably already in decline. Lichen is rarely found on healthy, vigorous trees.