Mulch
Mulch is simply anything you put on top of the soil. The purposes of mulch are five-fold:
1. To control weeds.
2. To reduce evaporation and keep water near the plant roots during the growing season.
3. To moderate the temperature of the soil and keep plant roots from scorching during a heat wave.
4. To protect your soil year-round – from water erosion, air erosion, frequent freeze-thaw cycles, and baking.
5. To add nutrients to the soil. (For a general discussion of soil and how to improve it, see Enhancing Your Soil.)
Mulches that are traditional in a veggie garden include:
➢ Grass clippings (no more than 2” at a time, so it doesn’t mat down and get smelly)
➢ Salt marsh haw and straw (not regular hay – too many weed seeds)
The classic book on mulching is Ruth Stout’s How to Have a Green Thumb Without an Aching Back. First published in 1955, it is delightfully and humorously written and helped transform home gardening in the U.S. Another of her classic titles is Gardening Without Work: For the Aging, the Busy, and the Indolent. Anything by Ruth Stout will inspire you as to the use of mulch.
➢ Compost (home-made or purchased)
➢ Weeds (as long as they haven’t started to set seeds you can just pull them out of the ground, lay them down, and consider them mulch; if it’s a wet day make sure the roots are exposed to air so they won’t re-grow into the soil)
➢ Newspapers (don’t use glossy pages in any garden, and try to avoid high-color pages in a place where you’re going to grow food)
➢ Planters’ paper (black paper on a roll – easy to lay down, decays in a season, helps control weeds, can be covered with a different mulch as well)
➢ Black plastic (good at blocking weeds, but not bio-degradable; put weeper hoses underneath the plastic and consider putting another lighter-colored mulch on top of it, so the soil doesn’t get too very hot)
➢ Red plastic (said to increase tomato harvests)
Mulches that are traditional in a perennial garden and around trees include:
➢ Wood chips
➢ Shredded bark
➢ Pebbles and stones (appropriate for plants that like hot soil and don’t like wet feet)
You may notice a pattern here. In a veggie garden, or around other annual plants, it is traditional to use mulches that will break down in a year or so, while around long-lived plants it is traditional to use more long-lived mulches. Soil scientists have recently figured out that these traditions have good reasons for them: quickly decaying mulches encourage bacterial growth, which is good for annual plants, while long-decaying mulches encourage fungal growth, which is good for perennial plants, including shrubs and trees.
I encourage you to use mulches that will break down and add to the fertility of the soil, especially if you can find them locally. Pebble mulches, however, definitely have their place around heat-loving plants. Just avoid mulches that contain weed seeds or heavy chemical loads (e.g., glossy newspaper inserts). Other than that, feel free to use your creativity!
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