Home >> Science & Nature >> Nature

How to Remove Lichen on a Tree Trunk

Lichen, a composite plant growth, is essentially a fungus containing photosynthetic algae cells. These growths get the majority of their water and nutrients from the atmosphere, unlike typical fungi which lack the chlorophyll to engage in photosynthesis. One way to kill off lichen growth is by using a spray known as a "Bordeaux mix," a combination of copper sulfate and hydrated lime.

Since lichen is considered completely benign, removing it should be considered an aesthetic choice. Also, keep in mind that the effect of using copper sulfate is temporary. Yearly applications will be necessary.

Things You'll Need

Full-face respirator
Long rubber gloves
Pump-handled garden pesticide sprayer
1 lb. of hydrated lime powder
1 lb. of copper sulfate powder
Two clean plastic buckets
Long-handled stirring spoon

Instructions

- 1
  Put on your rubber gloves and respirator. Pour one gallon of water into a plastic bucket, followed by one pound of hydrated lime. Stir the mixture to thoroughly combine and let the lime in the mixture sit and dissolve for two hours.
  
  Remember to use hydrated lime for this step. Regular garden lime will not be effective for the purpose of killing tree lichen.
- 2
  Pour one gallon of water into another plastic bucket, followed by 1 pound of copper sulfate and mix thoroughly to combine. Let the mixture sit for at least two hours to dissolve fully.
  
  Remove the respirator and gloves until you are ready to combine the two solutions for spraying.
- 3
  Put your rubber gloves and respirator back on. Pour equal amounts of your diluted lime solution and your diluted copper sulfate solution into the tank of a pesticide sprayer. Secure the cap on the tank opening.
- 4
  Pump the handle of your pesticide sprayer, aim the nozzle at the tree trunk and press the trigger of the sprayer to release the copper sulfate/lime spray at the trunk. Thoroughly saturate the trunk of the tree from top to bottom and on all sides. Try to spray with the wind at all times; you will probably need to adjust your position constantly to ensure that the spray is not blowing back in your direction.

Nature