Mulch is a workhorse in the garden. It suppresses weeds and regulates soil temperatures. It also helps hold moisture in the soil -- especially important this past summer. To get the most benefit of water conservation, make sure the soil is damp before applying a layer of mulch.
In winter, mulch keeps on working, using its power of insulation to help plants ease into winter dormancy more slowly and then to resist frost heaving. The thawing and freezing cycles of early spring can heave plants right out of the ground, exposing them to freezing temperatures. In this case, mulch keeps the soil cold longer so plants stay safely dormant.
Mulch may even protect plants from soil-borne diseases by keeping spores in the soil from splashing onto plants during rain or watering.
Many materials can be used as mulch. Which mulch you decide to use will depend on the look you'd like for your landscape.
Your vision may include a layer of stone. Or you may prefer the natural, earthy look of one of the wood mulches -- chips or finely ground. Vegetable gardeners may be satisfied with landscape fabric or dried grass clippings.
Mulch can be divided into two groups -- organic and inorganic. Inorganic mulches do not decompose like plastic, landscape fabric and rock. In addition to their other abilities, they can be used to hold heat (black plastic) or reflect heat (white stone). Inorganic mulches tend to be more expensive and last longer in the garden, although they add nothing to the soil.
Organic mulches add nutrients to and improve the structure of your soil as they decompose. These can include inexpensive and readily available materials like newspaper, cardboard, dried grass clippings or leaves, and garden compost.
Composted manure, pine needles, and hardwood mulches are other organic choices. In winter, use the boughs of Christmas trees as mulch. Spread them over perennials like coral bells known for frost heaving.
The amount of mulch needed depends on which material you have chosen for your landscape. The general rule is the smaller the pieces, the thinner the layer of mulch. A layer of weed-free straw would be much thicker than one of grass clippings.
When mulching, keep a small mulch-free ring around plants. Mulch over a plant's crown can cause it to rot. And please Ö help rid the world of mulch volcanoes around trees. Mulch up against the trunk creates the perfect environment for diseases and rodent pests.
As leaves begin falling from trees in the fall, use them to give your perennial beds a winter blanket. Be sure to run over them a couple times with your lawn mower or shred them before spreading. Early spring freezing and thawing will start working all that rich organic material down into the soil while you are sitting inside reading seed catalogs and dreaming of spring.
• Diana Stoll is a horticulturist and the garden center manager at The Planter's Palette, 28W571 Roosevelt Road, Winfield. Call (630) 293-1040 or visit planterspalette.com.