Learn About Lichens: The What, Why, & Hows All Homeowners Need To Know

What are these little green things growing on the bark of my trees? They are Lichens, and here’s what homeowners need to know.

Hey there, homeowners! Have you ever noticed those fascinating, moss-like patches on your trees? Those are lichens, and they’re pretty common in the our area. Let’s dive into what lichens are, why they’re not harmful to your trees, how they can actually benefit your trees, and how you can control or eliminate them if you choose to.

Lichen On A Tree

What Are Lichens?

Lichens are a fascinating and often misunderstood component of the natural world. Lichens are a unique combination of fungi and algae (or cyanobacteria) that live together in a symbiotic relationship. You might notice them as those colorful, often crusty patches on tree bark, rocks, or old fences. The fungi provide a structure and protection, while the algae or cyanobacteria use sunlight to produce food through photosynthesis. They don’t harm the surfaces they grow on and can come in various colors and textures, adding a natural, decorative touch to their environment.

close up of Lichen

Why Lichens Do Not Harm Trees

First things first: lichens are not harmful to your trees. Here’s why:

  1. Non-Parasitic: Lichens aren’t parasites. They don’t draw nutrients from your trees. Instead, they make their own food through photosynthesis, using sunlight and air.
  2. Surface Dwellers: Lichens use the tree bark as a place to anchor and grow, but they don’t penetrate deeply into the bark or harm it.
  3. Lightweight: Unlike heavy vines that can weigh down branches, lichens are light and don’t add significant weight to your trees.

So, if you’re worried that those patches are hurting your trees, breathe easy—they’re just along for the ride!

Lichens and mold on a tree

How Lichens Benefit Trees

Believe it or not, lichens can be beneficial to your trees and the surrounding environment:

  1. Air Quality Indicators: Lichens are sensitive to air pollution. Their presence often indicates good air quality, which is a great sign for your local environment.
  2. Wildlife Habitat: Lichens provide food and habitat for various small creatures, like insects and birds. This supports a healthy and diverse ecosystem in your garden.
  3. Moisture Retention: Lichens can help keep the bark moist during dry periods, which can benefit the tree.
  4. Biodiversity Boost: They add to your yard’s biodiversity, contributing to your garden’s overall health.
A full picture of Lichens

How to Control or Eliminate Lichens

While lichens are generally harmless and beneficial, some homeowners might prefer removing them for aesthetic reasons. Here are some ways to control or eliminate lichens on your trees:

Non-Chemical Methods

1. Manual Removal:

  • Soft Brushes: Gently scrub the lichens off with a soft-bristled brush. Be careful not to damage the bark.
  • Water Spray: Use a strong jet of water to dislodge the lichens. This method is gentle on the tree and can be quite effective.

2. Environmental Adjustments:

  • Increase Sunlight: Trim back nearby plants or branches to allow more sunlight to reach the lichens, which can discourage their growth.
  • Improve Airflow: Prune your trees to improve airflow around the branches, reducing the damp conditions that lichens love.

Chemical Methods

1. Lime Sulfur:

  • How to Use: Apply a lime sulfur solution to the affected areas. Follow the product instructions for the best results.
  • When to Apply: It’s best to apply during the tree’s dormant season to avoid damaging foliage.

2. Copper Sulfate:

  • How to Use: Spray copper sulfate on the lichens. Again, follow the product’s instructions carefully.
  • Caution: Use sparingly, as copper can accumulate in the soil, potentially harming the tree and other plants.

3. Commercial Lichen Control Products:

  • What to Use: There are several commercial products designed to control lichens. Look for products that are safe for trees and follow the label instructions.
  • Effectiveness: These products often combine fungicides with other ingredients that help break down lichens.
Lichen growing on a tree close up

Wrapping Up

Lichens are a unique and interesting part of the natural world in the mid-Atlantic states. They’re not harmful to your trees—they can indicate good air quality and support local wildlife. But if you prefer a lichen-free look, there are safe and effective ways to remove them.

Remember, lichens are more than just tree decorations—they signify a healthy, vibrant ecosystem. So, next time you spot them on your trees, take a moment to appreciate these incredible organisms!

Happy gardening, everyone!


Leave a Comment

Your email address will not be published. Required fields are marked *