Wednesday, 4 June 2014

Research - Using Mowed Grass for Mulching Trees

Readily available mowed grass, or grass clippings, makes excellent tree mulch. The amount of clippings used around trees depends on how dry the soil gets. One of the main reasons for mulching trees is to keep the soil moist. If your area has a sandy soil that dries quickly, layer 3 to 4 inches of grass clippings around each tree. For moderately dry soil, cut that depth in half. Mowed grass also keeps weeds down, because of the lack of sunshine getting to them, and the soil temperature more even -- cooler during summer and warmer during winter.


Mow your lawn. Spread the grass clippings out in a thin layer. A patio or an area protected from the sun is ideal. Allow the clippings to dry completely. This should take two or three days. Transport the dry mowed grass to the trees to be mulched. A wheelbarrow works well for this job.
Rake a 1-inch layer of mowed grass evenly around each tree. Leave a 4- or 5-inch clear space around the trunk. The grass should be spread out so that it extends 3 to 6 feet from the tree trunk and thus covers the tree root area. The diameter of the tree's branches is generally the same as that of its roots.
Pour another 1-inch layer of mowed grass after the first inch has dried. Repeat the process as more layers of grass clippings are needed.
Place additional thin layers of mowed grass around trees as they are available and are needed. Grass clippings decompose and blow away with the wind quickly. Therefore, it is an ongoing mulching process with this material.
Tips & Warnings
·     Do not place thick, freshly mowed layers of grass clippings around trees. Such clippings have a tendency to mat, which in turn causes a bad odour and stops air and water from penetrating to the tree roots.
·    Mounding grass clippings around the trunk of the tree is not advised. They can hold moisture at that location, which may cause the tree's bark to crack. This can leave an opening for fungus, disease or insects.

Proper mulching prevents soil erosion, and prevents light from reaching the surface of the soil.  Can enrich the soil by adding nutrients, using the product obtained from composting as  mulch acts as a good fertilizer.  (Talking about trees with open/muddy ground around and using composted grass as a mulch).

How much to Mulch:   Mulches should be around 2-4 inches high for trees.  This is the appropriate height required that gives effective covering to the soil.  The constituting substances used helps in making an easy decision.  If the mulch is made of compost, the thickness will be about 1-3 inches; if leaves; 4-5 inches; peat moss 1 inch thick.

How to mulch.

Clean the area before mulching.  Remove all grass, weeds and leaves near the tree, create a circular border (at least 3 inches diameter), spread the mulch to required thickness, settle by watering.

Useful Tips.

Prepare mulch according the type of tree or plant.
Do not pile up the mulch against the stem of the plant or tree trunk.
If you are using organic mulch, keep it well aerated and well drained.
If you face drainage problems with the mulch, decrease an inch of the thickness.
Prevent excessive moisture in mulch, as this might lead to rotting of the roots.
Excessive mulching may lead to infestation by rodents and spread of certain diseases.

Spread the grass clippings out in a single layer. Use a dry patio or other sheltered area where the sun will not shine directly on the grass clippings.

Let the grass clippings dry.  Can take 2/3 days depending on the weather

Apply 1 inch of grass clippings around the base of each tree. Rake the grass clippings out about 3 to 4 feet away from the tree. Don't push the grass clippings up against the tree trunk, but leave a space of 2 to 3 inches between the mulch and the trunk.

Apply additional 1-inch layers of grass clippings once a week as you mow your lawn. Because the grass decomposes quickly, regularly application is necessary for it to be an effective mulch.


·     Don't use fresh grass clippings as mulch for your trees. Fresh grass can cause a solid mat to form, which will prevent the tree from taking advantage of water and circulating air. Fresh grass can also encourage disease and unpleasant odours to develop as it dries and decomposes.

Are grass clippings used as mulch good for trees?
I've heard conflicting information regarding grass clippings. I used clippings as mulch around trees. Some people say it's good for the trees; some say it may give the trees a disease. Who is correct?
Submitted by BHGPhotoContest

Good mulches for the base of a tree include wood chips, pine needles, and shredded bark. You can use grass clippings, too, but be aware of a few things. If you put down fresh grass clippings in a layer more than a couple of inches deep, the clippings can form a mat that discourages air from penetrating the soil. This mat will eventually rot and smell bad. Make certain that the grass from which the clippings were cut has not been treated with any herbicides that might be harmful to trees. Grass clippings and other organic mulches won't directly harm trees, but they can harbour rodents in winter that feed on the bark. To reduce the chances of rodent feasting, as winter approaches pull mulch away from the trunk. Wrap young trees with hardware cloth or tree wrap.

 Mulch can kill trees

Mulch can kill trees–that sounds kind of extreme, doesn’t it? But it caught your attention, right? I suppose it would be more accurate to say improper mulching can kill trees, but as I look around me, improper mulching of trees seems to be the standard practice, the only kind of mulching around trees that’s being done.   ...... they apparently didn’t realize that the way they mulched the trees would eventually kill them.

How does mulch harm trees?
When you put mulch around the trunk of a tree and cover the root flare, you are covering up parts of the tree that were meant to be exposed to air. The excess moisture can cause rot, but the trunk of the tree is supposed to have access to air, and by piling up mulch against the bark you are preventing this. If the mulch is left there long enough, the tree will try to compensate by growing adventitious roots. Unfortunately, these same roots can wind up wrapping around the tree and girdling it.

The tree winds up killing itself. So we have three ways improper mulching can kill a tree:

1.       rot
2.       suffocation
3.       girdling

In addition, the stress of improper mulching could make the tree more vulnerable to a secondary problem, such as an insect infestation.

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