Gardening with Gary

Gardening Advice from an Expert

Mulch

Q. I recently saw on TV that if you put mulch around a plant you push the mulch away from the base of plant. I have a mixture of winter dead grass, lots of cutup leaves, and wood chips. I am going to use it this summer. Why did they say to clear it away from the base and is it necessary?

A. Some gardeners recommend this pushing the mulch away from the stem of the plant to ensure that water will get down into the central root system. Mulch, especially dried cut lawn grass, can get matted and lay almost like a blanket. Though this is great for keeping the soil moist right below it and the temperature cool, it can shut off additional water from reaching the roots.

Lay the mulch around the plants as always, and then just take your hands and move a bit away from the circumference of the stem [or trunk]. If you are dealing with a multitude of plants growing together, loosely lay the clippings onto the soil all around them and poke some holes through it so that rain or your watering will reach through the dense mat.

I must say that it is not essential if you do not wish to do it. I think the advisor was fearing the worst. If you see that your mulch of any kind is keeping the water from penetrating, then you can take appropriate action.

T.A. writes~ We live in NW Arkansas, in the Ozarks, and water is short in late summer. I have used oak chips as mulch around my fruit trees. Do mice make nests in the mulch and eat the fruit trees roots? Is oak too acidic for fruit trees? What can I add to the oak acidity to equalize it? Does decomposition of the oak chips cause a problem?

A. Oak chips are fine for all trees. Mice may make nests in the chips, so you may wish to mix leaves in finer size with the chips. Any chipped or shredded wood will be good mulch. The best type is small, medium and large-sized particles all mixed together; chips under 1" and up to 3-4" in size. Chips from diseased elm or oak are safe to use. Once chipped, this wood cannot spread Dutch elm disease or oak wilt. Superphosphate is added according to directions to raise the pH of acidic soils. Mulch all new plantings at planting time. Mulch the base of your tree in a circle 2.5-3" from the trunk. Use hay, straw, compost, bark chips, wood shavings, leaves provided the product is natural and does not form an impervious mat. Ensure that the mulch is applied to a depth that prevents weeds from growing through. Replenish yearly.

Fruit trees find ways to cope with even the most adverse soil conditions as long as you feed them properly and keep organic matter around their roots in the form of mulch. As the mulch decomposes and the soil conditions improve, you will begin to see increased yields and fewer problems with pests and diseases. Make sure that each year the mulch layer is supplemented with additional mulch to accommodate the tree's increased branch spread.

Wood chip mulch is easily applied with regular garden tools. Simply put down 3-4" of chips, level off and tamp lightly, pulling chips away from trunk slightly. There is no need to use plastic sheets with rocks. Rocks hold heat and can be detrimental to plant health.

Benefits of mulching with wood chips:
Saves Labor - no weeding, less time watering
Saves Water - far less watering needed, and more rain absorption
Safer - no need for chemical weed killers or herbicides
Stimulates growth - mulched trees grow faster than unmulched trees
Makes trees more resistant to disease and insects
Keeps soil and roots from overheating in hot summers
Eliminates injury to trunk from mower collisions
Reduces soil compacting over roots and adds loft
Nourishes the soil by adding nutrients as it decomposes
Eliminates the need for tilling and resultant root injury
Reduces bruising of fallen fruit under fruit trees
Increase earthworm population resulting in better aeration

Fruit trees need at least two good mulchings (10" thick) a year, one before the summer heat and one after the mulch has broken down during the wet fall. The mulch will provide the ground and your tree's roots with shade from the sun, lower the soil's temperature, give worms food and a place to hide when they are forced to the soil's surface after a rain, and slow the evaporation of precipitation and condensation at the soil's surface. In the dryer months, mulch lasts longer and does not break down as quickly as it does in humid conditions.

Compiled from Don Trotter, The Permaculture Institute, and The Minnesota DNR.