Tips and resources for farmers and gardeners
Mulching can reduce rotting by keeping vegetables such as squash and tomatoes out of contact with soil. Organic mulches also lessen soil compaction, slow down erosion and improve soil texture when later tilled into the soil.
To get all these benefits, however, you have to think ahead and consider your own particular situation.
Choose Your Mulch
Mulches have characteristics homeowners should consider when choosing which to use.
Shredded Newspaper or Dry Leaves
Both tend to be available at no cost and are easy to plow under, but they are dry and will blow away in a good breeze
Use grass clippings with caution. If you have applied a broad-leaf weed killer to your lawn, there may be residual herbicide on them.
Peat moss can be costly. It’s so fine-textured that rain can easily make it mat or wash away down a slope. Even so, peat moss probably is the easiest soil-improving mulch to incorporate. It also looks natural and won’t introduce pests into the garden.
Local Straw, Hay or Compost
These may contain weed seeds, and they may not be very attractive in the home landscape. However, all three materials are easy to incorporate into soil after providing a season’s protection. In fact, the compost will be almost the same as enriched soil by the end of summer, and both straw and hay can provide fairly deep protection without matting.
Wood chips from the local landfill usually decompose at an uneven rate. And, some mixes won’t look too ornamental until they’ve aged for a while. Mixes can and usually do include chips that could attract wood-eating insects, so they may not be totally safe next to a home. Nonetheless, they often are inexpensive or free, and they look more natural and last longer than thinner, finer mulch materials.
Sawdust and wood chips both are dry and easy to spread. Plus, they usually contain few weed seeds or disease pathogens.
Among the inorganic mulches, black plastic can perform well in spring, but it will require shade or plant foliage cover in summer to keep it from making the soil too hot for plants. If it’s not perforated, plastic also can keep air, water and nutrients from reaching the soil.
Landscape fabric is a porous material that lets water in, but keeps most weeds from growing up into your bed. No mulch will give you 100 percent weed control, but there are different grades of landscape fabric, some of which will last much longer than others, so be sure to read the label. It may not need an organic mulch on top, but gardeners generally apply one anyway, just to improve its looks.
Inorganic mulches vary in how long they last, depending on the product and its exposure to the elements. Their durability also changes with the number of times gardeners you cut it into the plastic/fabric to add new plants.
Rocks and gravel are good in windy areas. They should be applied 2 inches to 4 inches deep. They tend to absorb and reflect heat, so be careful not to put them around cool-loving plants.
You can apply mulches directly to the soil or over landscape fabric.
Chuck Marr, Kansas State University Horticulturist
Cheryl Moore-Gough, MSU Extension Horticulturist