A lot of homeowners think of mulch as strictly cosmetic, just something to make the place look good. And it’s true that mulch around the base of trees and shrubs does improve property appearance.
But there’s so much more that mulch can contribute to your landscape. It makes lawn and tree maintenance a whole lot easier, and provides other yard care benefits that are underground and out of sight.
Managing Soil Temperatures For Better Tree Growth
Proper use of mulch is an essential tree care technique. Tree roots are sensitive to high summer temperatures. When the surface soil reaches 100 to 108 degrees, or more (which it can during hot weather), most tree roots begin to die. Temperatures that high simply kill the roots. Unfortunately, this happens in the upper area of the soil (the top 5 to 6”), which is usually the most fertile. A 3” layer of mulch can reduce soil temperatures by as much as 10 degrees, maintaining a healthy growth environment for the roots, and letting them grow actively in the upper soil.
There Are Other Yard Care Benefits, Too
Mulched soil retains moisture much better than bare soil can around your trees. This means watering less and reducing the chance of water stress on the trees. Mulch cuts down soil erosion, or wash-out, around trees. It reduces soil compaction, and can improve soil structure as the mulch breaks down. Mulched barriers around trees keep mowers and trimmers from causing mechanical damage to the trees.
Many Materials Available As Mulch
Mulches are either organic or inorganic. Organic choices include bark chips and shredded bark (of which there are many kinds commercially available); wood shavings; sawdust; peat moss; cocoa hulls (a great smelling choice if you like chocolate!); straw or pine straw; rice hulls or crushed corn cobs; and yard waste like leaves, grass and twigs. Those in the yard waste group are not widely used because they usually don’t improve property appearance as much as the commercially produced mulches. Inorganic mulches include gravel (or crushed rock), a variety of sheet materials (like plastic), and several types of shredded rubber or tires.
Of the commercially produced mulches, costs vary greatly depending on the area of the country, but overall, wood and bark products are the most common and economical.
A Couple Of Quick Pointers On Mulching
If you mulch in the fall, wait until the first really cold snap is over before tackling this lawn and tree care step. By then, most ground-burrowing rodents have settled themselves for the winter. If you mulch earlier they may decide to move into your beds. You should keep mulch from piling up around the trunk. Don’t keep adding to the top of the pile each year, as this can cause rot, disease, and insect problems at the base. Apply mulch 2 to 5” deep after removing grass and weeds, and cultivating the soil.
- Mulch reduces soil temperature as much as 10 degrees — enough to make a difference between supporting or killing tiny feeder roots near the surface.
- Mulch applied around your trees each year reduces water stress, weeds, and damage to trees.
- Many materials work well as mulch, with wood products being the most common.
- Don’t mulch in early fall, preventing mice and ground squirrels from nesting in beds.
So, besides helping the place put on a happy face, Spring-Green suggests mulching every year as part of your yard maintenance plan for all the good health it delivers. Combine mulching with time-tested techniques like core aeration and proper fertilization to keep your lawn healthy and happy for years to come.
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