Putting Down Mulch Step-By-Step

A layer of mulch is more than just a cosmetic dressing on your garden. Done right, mulch will suppress weeds, help keep the soil damp and, if you use organic mulch material, improve the soil texture. You can choose from organic mulch materials or inorganic mulch for your garden. Spring after the soil warms up is the best time to mulch, but you can also mulch in summer and early fall.

Mulch will suppress some weeds from growing by smothering the seeds, but you have to start with a clear area first. Putting down a layer of mulch over a weedy garden will do little to control weeds. You can use a hoe to dislodge shallow-rooted weeds. For deeper, established weeds, dig down deep enough to get the tap roots out. Rake the area flat after pulling weeds.

Organic mulches, like wood chips, leaf mold, compost, manure, grass clippings and straw, break down through the year and improve the soil texture. Spread organic mulches between 2 and 6 inches deep. Use a deeper mulch layer, to 4 to 6 inches, when using large, loose mulch, like straw or wood chips. For denser mulch, like sawdust and grass clippings, use 2 to 3 inches of mulch. Soil needs air and circulation. Spreading a layer of mulch too deep can interrupt the natural processes.

Shovel the mulch onto the soil in the garden area. When mulching trees and shrubs, extend the mulch out at least 3 to 6 feet. Ideally, bring the mulch out the drip line, the area under the tips of the branches where water would naturally drip, to cover the whole root zone. Mulch annual and perennial garden beds out to the edge of the bed. Leave 1 to 2 inches between the base of a plant, or the trunk, and the mulch layer. Rake the mulch flat to distribute it evenly.

To put down plastic mulch, spread it over the garden bed, cutting out holes for plants as you go. Secure the plastic using bricks or stones. Before putting down plastic mulch, it's a good idea to put down a soaker hose around the plants. Black plastic doesn't allow moisture in and can cause the garden to dry out. Alternatively, you can water each plant deeply at the base. Plastic mulch works well in the vegetable garden where it can help warm up the soil, but in a landscaped areas, it can be unsightly.

Pea gravel makes an attractive inorganic mulch layer and is particularly well suited for cactus and succulent gardens. Spread the gravel 2 to 4 inches deep over the garden bed and smooth it out. In weedy areas, put down a layer of plastic before you spread the gravel mulch layer. Pea gravel can be hard to keep clean in areas where a lot of leaf litter or pine needles tend to fall. You can rake out big leaves, but eventually they break down and get between the stones.