“What is this scaly grey stuff growing on my plants? Some of it looks like scale, some is bearded and some is like a paint splash on the bark.” I wish I had a dollar for every time I have been asked that question over the many years I have spent gardening and teaching others about the wonders of gardening. This strange and interesting plant is Lichen pronounced “liken” in America. It is a symbiotic plant which means that it is two different plants living in harmony with each other. One is a fungus which provides the structure, and the other is an algae which provides the chlorophyll and thus feeds the plant.
Lichen is found in many forms. One form even looks like and feels like a sponge when moist and is dry and crackly when dry. This one is called Reindeer Moss, because it actually grows prolifically in the areas of the world where reindeer live. I can attest to that as a fact because I was privileged to see them eat it like cows eat hay. Another form is very tiny and has little red tips on tiny stalks. It is often referred to as British Soldier. Lichen colors range from gray to green to yellow to orange. It can be seen on trees, shrubs, soil, logs, and rocks. About 18,000 species have been identified.

Lichen is not a parasite that harms your plant. It is a plant that reveals something about your plant that you need to know. If your plant is actively growing and healthy, lichen cannot stay attached to the branches – the expansion of the stems during growth will shed the lichen. So, why is it on the plant? Why isn’t the plant growing? Maybe it is just too old to put on fast growth, so we see it on large trees. We see it on dead branches on trees and when they fall to the ground. When we see it on living branches, it tells us that the tree is not growing rapidly – maybe because the soil is too soggy or brutally hard and the root system is not developing properly. Maybe because the plant is not getting the proper amount of sunlight (too much or too little). Maybe because the plant is not getting the nutrition that it needs, or even that it is planted too deeply. There are so many reasons for a lack of rapid growth.

Lichen can be seen often in plum bushes growing along a country road. They grow in heavy clay, but cannot grow rapidly. This will often be the scaly form along with the bearded form – interesting and pretty. Don’t be afraid to examine it thoroughly when you see it. It is not toxic.

You will observe Reindeer Moss most often on North facing slopes or ground under pine trees. The colder location and the poor soil contribute to this fact. Look for it as you drive around. British Soldier lichen is often seen when walking through a pine woodland on poor soil and among pine needles on the ground. This winter season is a wonderful time to stroll around and observe all the different forms of lichen on and under trees and shrubs – growing in the worst of circumstances.
Now that you have all this information, how can you get your plants to shed the lichen and begin to grow? First, analyze why your plant is not growing. It is not getting what it needs – good drainage in the root zone and/or poor nutrition from the soil. Try this – aerate the soil with a spading fork by making multiple holes in and around the root zone. Then apply the proper amount of a slow release fertilizer which will be spread into those tiny holes. Water and apply a mulch. Do this in March.

If by June you do not see an increase in growth, it may be that the root system is continuing to be damaged by a lack of water drainage. This will have to be a larger task of digging up the plant and amending the soil or raising the area or providing a drainage system, then replacing the plant in the soil if it is not too damaged. You may want to hire a qualified professional before you begin this effort.

Scientists continue to study this fascinating plant and have found that toxic species have a second invading fungus. More information is needed about the many forms of Lichen, but you need not fear this plant, just be amazed at it. This is a great plant to explore with your children.