Back to Timely Topics on HorticultureGary Wade and Wayne McLaurin, Extension Horticulturists
Landfills in Georgia are filling up fast, and citizens everywhere are recycling in an effort to reduce curbside waste.
Landscape refuse, such as leaves, grass clippings, and trimmings, accounts for 20% of the waste dumped in landfills.These valuable organic materials can be easily recycled and added back to the landscape as mulch.
Mulching is one of the most beneficial gardening practices in our southern landscapes. Mulches conserve moisture, insulate the roots of plants from temperature extremes, and help control weeds. They also provide a barrier to certain soil-borne diseases that feed on plant foliage.
As organic mulches decompose on the soil surface, they add valuable plant nutrients to the soil. They also protect sloping ground from soil erosion and prevent soil compaction from driving rains. Mulched areas require little routine maintenance and can save you time and energy in the landscape.
Fall leaves, grass clippings, pine straw, and trimmings are excellent mulches for the landscape or vegetable garden. Large leaves and twigs should be shredded before they are used as a mulch. A simple way to accomplish this is by placing them in small windrows, six to eight inches high and two feet wide, on the lawn. Then, with the lawn mower set for the highest cutting height, run over the row once or twice. A grass catcher attached to the mower is handy for this operation. Some equipment companies sell mulching attachments for lawn mowers.
A mechanical grinder or chipper is needed for large limbs and stumps. Some local utilities, public works departments, and tree service companies will grind large material for you. Check with your local government for recommendations.
Medium and fine-textured mulches are less likely to be scattered by the wind, do a better job of conserving moisture, and become seated on the landscape better than coarse-textured materials.
A mixture of several different organic materials provides the most attractive and uniform appearance on the soil surface. Some fine-textured mulches, like grass clippings, tend to mat down and decompose quickly when used alone.
Place three to five inches of mulch on the soil surface under trees and shrubs. On newly planted ornamental trees and shrubs, extend the mulched area at least six inches beyond the canopy spread. Then gradually expand the mulched area as the plant grows. The roots of established ornamental plants spread two to three times the canopy spread of the top, so mulch as large an area as possible.
Once in place, pull back the mulch to three inches from the main trunk to avoid possible wood decay. Then moisten the surface to help settle the mulch and to prevent it from blowing away.
Mulch can also be used on flower beds, on the surface of container plants to help conserve moisture, under berry bushes and fruit trees, and in the vegetable garden.
If you have an over-supply of mulching material during the fall leaf season, think about expanding your shrub beds to create smooth flowing islands of natural mulch. Also consider composting excess mulch, tilling it into the winter vegetable garden, or giving it to your neighbor for his landscape or garden.
Store a few bags of mulch for use in insulating plants during a winter freeze. Mulch provides and excellent insulation against winter cold. When severe weather threatens tender ornamental plants that cannot be moved indoors, construct a wire frame around the plants and fill it with mulch. Then, remove the frame and mulch as soon as warm weather returns. A blanket of mulch will also protect the roots of containerized ornamental plants from winter cold.
Be creative when using mulch. Consider using it in animal pens, on garden paths, and along fence rows to help prevent weeds. The possibilities are endless.
Recycling Mother Nature's riches will help save our valuable landfill space.
Q: Why would more than five inches of mulch be harmful to ornamental plants?
A: Excess mulch will prevent much needed oxygen from reaching the roots of plants and will encourage the roots to grow out of the native soil into the mulch layer where they can be injured by drought or cold temperatures.
Q: I've heard that fresh sawdust will rob nitrogen from my soil. Is this true?
A: Not if it is used as a mulch instead of an amendment. Avoid incorporating fresh sawdust into the soil.
Q: Will pine straw or oak leaves make my soil too acid
A: No, mulching materials have little affect on soil pH.
Q: Is there any yard refuse that should not be used as mulch?
A: Avoid using grass clippings if they contain weed seeds or if the grass has been recently sprayed with weed killer.
Q: Is it necessary to remove old mulch and replace it each year under ornamental plants?
A: No, simply replenish the existing mulch with a fine layer of new mulch on the surface. The old mulch will decompose and add valuable humus to the soil.
The University of Georgia and Ft. Valley State College, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.
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Issued in furtherance of Cooperative Extension work, Acts of May 18 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.
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