The mountains or volcanoes or whatever you want to call them are still being created by dumb landscapers and their staff. I’m referring to those mounds of mulch that many landscapers and homeowners load up around the base of small trees. Those mounds sometimes cover as much as ten inches of the trunk of the tree. They drive me nuts.
Guess what? Those mulch mountains are slowly killing those trees. It is tree murder. That piled mulch keeps moisture up against the bark of the tree and leads pest insects and disease spores into the tree like an open doorway. Why do people and landscapers continue year after year to slowly kill small trees? It is a mystery to me. The rule is simple. Never let mulch around the base of a small tree touch the bark of the tree. The circle of mulch can be three to four inches deep, but in the middle of the circle the trunk is kept bare. The mulch layer should start about 6 inches from the trunk. We want doughnuts not mountains. This is not new information. It has been general knowledge among reputable tree care professionals for 25 years. The tree care companies that make mulch mountains are just plain ignorant and apparently don’t spend much effort to learn the right methods for mulching small trees. Homeowners see these mulch mountains and figure if the professionals make mulch mountains, maybe I should do the same. Unfortunately mulch mountains are not the only problem for small trees. Another major problem is that most people use no mulch around small trees. Or if they do use mulch it is not the best kind for the health of the tree. ANOTHER RANT ABOUT MULCH MOUNTAINS
Mulch Mountains
The mountains or volcanoes or whatever you want to call them are back. I’m referring to those mounds of mulch that many landscapers and homeowners load up around the base of small trees. Those mounds sometimes cover as much as ten inches of the trunk of the tree. They drive me nuts. Guess what? Those mulch mountains are slowly killing those trees. It is tree murder. That piled mulch keeps moisture up against the bark of the tree and leads pest insects and disease spores into the tree like an open doorway. Why do people and landscapers continue year after year to slowly kill small trees? It is a mystery to me. The rule is simple. Never let mulch around the base of a small tree touch the bark of the tree. The circle of mulch can be three to four inches deep, but in the middle of the circle the trunk is kept bare. The mulch layer should start about 6 inches from the trunk. We want doughnuts not mountains. This is not new information. It has been general knowledge among reputable tree care professionals for 25 years. The tree care companies that make mulch mountains are just plain ignorant and apparently don’t spend much effort to learn the right methods for mulching small trees. Homeowners see these mulch mountains and figure if the professionals make mulch mountains, maybe I should do the same.
Unfortunately mulch mountains are not the only problem for small trees. Another major problem is that most people use no mulch around small trees. Or if they do use mulch it is not the best kind for the health of the tree. Yes, most forms of mulch keep down weeds, slow the evaporation of water from the soil, and protect the small vulnerable tree trunk from damage from lawn mowers and string trimmers. But as important, mulch around a small tree needs to serve as food for the soil food web inhabiting the soil in which the roots of that tree must live. Soil with sufficient organic content will have over 5 earthworms per cubic feet and a tablespoon of that healthy soil will hold over a billion beneficial soil microbes (bacteria, fungi, and protozoa). The collective community of all the soil critters from big (earthworms) to small (bacteria) make up the soil food web. They break up compaction, help soil store water, and create food for plants. A well fed soil food web leads to healthy plants. If there is no layer of organic matter on the surface to feed the soil food web, the soil is essentially dead. Dead soil gives plants little support. So here is the complication. There are very few types of organic matter available in stores or from landscapers appropriate as mulching material that also serves as food for the soil critters. Bark chips and roughly shredded bark perform all the other mulching functions, but they are not appropriate as food for the soil food web. Earthworms can’t take bark chunks down into the soil. The best organic materials for feeding the soil food web are chopped leaves (more available in the fall), finely shredded bark (shredded with a tub grinder), or a mixture of commercial compost and Canadian sphagnum peat moss. You do not need four inches of this type of mulch around your small tree or shrub. A half an inch is plenty for the season. On top of the thin layer of critter edible mulch you can layer the bark chips or roughly shredded bark up to but no more than four inches. Now you have the best of all worlds. You are feeding the soil food web and you are keeping down weeds and protecting the tree from those clunky lawn mowers. Remember; doughnuts not mountains.
Would you believe that dead soil under any plant is a bad thing? So what about feeding the soil food web in the soil under existing turfgrass? Do I mulch my grass just as I should mulch my trees and shrubs? The answer is very definitely; yes. Mulch for the lawn is either finely chopped leaves, chopped by a mulching mower, or that mixture of compost and Canadian sphagnum peat moss. A half an inch of leaves or one eighth of an inch of the compost mixture layered on to the lawn every year will serve to feed the soil food web which in turn will slowly turn your compacted dead soil into gorgeous black loam allowing grass roots to finally get down six to eight inches where they belong. Rule For Mulching Trees
No Mulch Is Bad
Yes, most forms of mulch keep down weeds, slow the evaporation of water from the soil, and protect the small vulnerable tree trunk from damage from lawn mowers and string trimmers. But as important, mulch around a small tree needs to serve as food for the soil food web inhabiting the soil in which the roots of that tree must live.
Mulch Feeds The Soil Food Web
Soil with sufficient organic content will have over 5 earthworms per cubic feet and a tablespoon of that healthy soil will hold over a billion beneficial soil microbes (bacteria, fungi, and protozoa). The collective community of all the soil critters from big (earthworms) to small (bacteria) make up the soil food web. They break up compaction, help soil store water, and create food for plants. A well fed soil food web leads to healthy plants. If there is no layer of organic matter on the surface to feed the soil food web, the soil is essentially dead. Dead soil gives plants little support.
Finding Organic Mulch Is Not Easy
So here is the complication. There are very few types of organic matter available in stores or from landscapers appropriate as mulching material that also serves as food for the soil critters. Bark chips and roughly shredded bark perform all the other mulching functions, but they are not appropriate as food for the soil food web. Earthworms can’t take bark chunks down into the soil.
The best organic materials for feeding the soil food web are chopped leaves (more available in the fall), finely shredded bark (shredded with a tub grinder), or a mixture of commercial compost and Canadian sphagnum peat moss. You do not need four inches of this type of mulch around your small tree or shrub. A half an inch is plenty for the season. On top of the thin layer of critter edible mulch you can layer the bark chips or roughly shredded bark up to but no more than four inches. Now you have the best of all worlds. You are feeding the soil food web and you are keeping down weeds and protecting the tree from those clunky lawn mowers. Remember; doughnuts not mountains.
Would you believe that dead soil under any plant is a bad thing? So what about feeding the soil food web in the soil under existing turfgrass? Do I mulch my grass just as I should mulch my trees and shrubs? The answer is very definitely; yes.
