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Not All Plants With Lichens Are Dying

by Les Harrison

In a finite world there is always an end which sooner or later follows every beginning. The inevitable termination is rarely a surprise, but the signals and signs are often overlooked.

In home horticulture the unavoidable end of plants and trees can provoke many questions.  Aside from the self-recriminations, there is also the economic impact.

Few events engender attention to potential problems more than a pain in the pocket book. So if one plant exhibits symptoms and then dies, the remaining plants will be examined closely for similar signs.

Lichens often grow on dying plants, but not all plants with lichens are dying. Based on a few occurrences, it is easy to conclude they then are the cause of the shrubs demise.


Lichens are often associated with decline or death of plants and trees. Sometimes they will appear just to clean off the excess dead organic material on the surface of shrubs.

Lichens are composed of algae and fungi living together in a symbiotic fashion which is beneficial to both organisms. They are found in a wide variety of locations around the planet, including some exceptionally harsh environments.

The fungi play an important role in the nutrient cycling and organic residue decomposition.  They are responsible for the breakdown of dead organic materials so it may be converted into a useable form for utilization by another organism.

The algae processes atmospheric carbon dioxide into organic carbon sugars to supply nutrients both organisms.  By working together, albeit unconsciously, both are able to prosper in environments where they would individually fail.

Lichens can be found in a variety of locations in Wakulla County.  One of the most obvious, at least to homeowners and gardeners, is on parts of shrubs and trees.  In many cases the lichens are blamed for the decline of the plant or tree.

The reality is the lichens are opportunistic and are completing the natural cycle.  If the lichens were not on the job of consuming dead organic matter, something else would be required to reduce the material.

In north Florida there are several lichens with one, deer moss, not positioned on plants.  The grey-green clusters have a cloud-like appearance with a resemblance to Spanish moss, but are located exclusively on the forest floor.

Deer moss is very slow growing with large mats taking many years, even multiple decades, to develop. Florida’s natural fire cycle will usually kill this lichen species.  When large mats are encountered in the woods, it is an indication the area has not burn recently.

Deer moss has a miniscule root structure and gets its moisture from the air, like all lichens.  During periods of drought it will be crunchy and delicately fragile.

With rains, the ample moisture guarantees the clumps are soft and pliable. This rehydration process will take a short period and is common to all lichens.

Even before recorded history, lichens have had multiple uses, depending on the culture and time period. Some populations in northern Eurasia and North America have utilized lichens as food, occasionally on a regular basis but usually as a means of survival during famine.

Some of these same peoples have utilized lichens as a basis for textile dyes.  Modern synthetic dyes have replace most of these natural dyes.

Contemporary application for the lichens is as a janitorial service for dead plant material. All things considered, they are good to have on the job even though the circumstances are not ideal.

2 Comments on “Not All Plants With Lichens Are Dying

  1. I used to find a lot of deer moss on the empty lots around me. With the building that erupted in 2007/08, not so much but still around. I went out looking for some and couldn’t find any. That’s not totally unusual, but sometimes it’s there and other times not. I don’t see a season for their growth. Can I get some information on this other than what you already have here?
    Thank you

    • Hello Ms. Gail, sorry for the delayed response.

      Deer moss is a lichen species, a symbiotic relationship between a fungus and algae. Under the right environmental conditions they grow, albeit slowly. When the growing conditions are not favorable deer moss degrades and becomes less visible, usually residing under leaf litter and other forest debris. Also, fire from a controlled burn (or any other source) will kill lichens.

      Let us know if you have further questions!

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