If they could talk, everything from your peonies and cosmos to your tomatoes and eggplants would thank you for the daily boost they get from mulch. Spread over the surface of the soil to protect and improve its condition, mulch has a slew of benefits. "It retains soil moisture, helps prevent weeds, and helps replenish organic material," says Kurt Morrell, the A.P. Farm Associate Vice President for Landscape Operations at the New York Botanical Garden in Bronx, New York. As if that wasn't enough, it also regulates soil temperature and keeps soil from eroding.
Martha's favorite mulch is made of composted stable bedding. To find a similar product, contact stables in your area and ask if they use wood shavings as bedding (you may have to compost it yourself). Your local garden center may also know of a source. Coarse-textured mulches such as hardwood bark mixes work well under trees and in shrub borders. Use the finer grades such as chips or shredded bark, not the largest grade, which never breaks down into the soil. You can buy the mulch in bags at a garden center if you need to cover a large area, but it's also easy to create a lush, healthy mulch garden using items that would otherwise land in your trash—food scraps, cardboard, junk mail, dead leaves, sticks, twigs, and newspaper.
Read on for more tips on how to choose the right mulch for your garden beds.
Organic Versus Inorganic
Mulch comes in a large variety of forms, either organic or inorganic, and both are useful in gardens. Organic mulch materials come from recycled plant or chipped woody materials, which decompose over time and must be replenished eventually. They get a thumb's up for making soil more fertile and helping with drainage. Inorganic matter, which helps keep weeds away, never decays or needs to be replaced. Organic mulches include bark, tree branches, cedar, hemlock, pine needles, root mulch, wood chips, straw, grass clippings, shredded leaves, newspaper, cardboard, cocoa chips, compost, redwood bark, and sawdust. Inorganic mulches include rock, stone, landscape fabric, rubber, and plastic.
Use What's Around You
It isn't a matter of preference: Nature has decided which mulch material works best in each planting situation. Two criteria to base your choice on, according to Morrell, is what's available in your area and what are your garden's existing soil needs. "Try to use a mulch that is made up of different size particles," he says. This will assist in supporting a more diverse soil. Aesthetics counts, too—mulch can add color and texture to your garden. But avoid mulches that are dyed—they're likely made from recycled wood waste that contains chemicals, which will harm the soil.