Mulch







Mulch is a layer of organic or inorganic material laid on the soil around plants.

Mulch provides several benefits:

- helps keep weeds down
- lessens evaporation from the soil surface
- organic mulches add organic material and nutrients to the soil as they decompose
- provide temperature control
- helps keep produce cleaner
- some inorganic mulches can reflect heat, helping produce ripen
- limit soil erosion of cultivated garden areas

Organic Mulches

Here are some common organic mulches with application recommendations from Virginia
Cooperative Extension:

Hay or straw

Use a 6 to 8 inch layer. Both materials decompose readily adding organic matter and helping soil structure. They decay easily so hay and straw need to be be replenished to keep weeds down.

Compost

Great for amending to soil and building structure. Use a 2 inch layer. Weeds will
grow in the compost,so its not a good long term weed supressant.

Grass Clippings

Readily available. Preferably dry in a 2 inch layer, building up this layer gradually. Avoid adding clipping that had herbicides applied. Depending on the grass source, clippings may contain weed heads and seeds.

Sawdust and Shredded Bark

The American Horticultural Society suggests that sawdust and bark products should not be used unless it it is at least two years old. Its decomposition uses soil nitrogen. Other sources indicate that sawdust can be used, however, nitrogen should be added at the rate of 0.5 pounds per 10 cubic feet of sawdust (2 to 3 contractor wheelbarrows full). Apply 2 inches of sawdust mulch.

Other Organic Mulch Possibilities

Local conditions determine the availablity of other mulches. They include composted
animal manure, spent mushroom compost, peat moss, seaweed, pine needles.

Inorganic Mulches

Landscape Fabric

Make sure the fabric is not a water barrier. Spread it out across the plot and staple in place. Cut X's and plant in the exposed area. I have used this technique very successfully with tomatoes. No weeding at all expect for an occasional stray growing up through the cut hole. Makes you almost long for a weed to pull! End pieces of fabric are sometimes available from commercial landscapers.

Plastic Sheets

A wide variety of products, including black, white, red, and transparent. A single sheet will do. Use wire staples or stakes to affix the edges. Also, it helps to bury the edges. White or and reflective plastics are used to reflect light to help produce ripen. Reflective surfaces reportedly "annoy" pests. Red plastic reportedly increases the yield of tomatoes by 20 percent and enhance the flavor of strawberries.

Newspaper

A few layers of newspaper held in place by a light cover of organic mulch can last the season and degrade into the soil. These days, concerns about chemcials in ink are mostly related to some colored inks. Black ink is generally lead free.

Dos and Don'ts

- Do place mulch after the soil warms and dries out slightly;avoid placing on wet, cool soil
- Don't pile mulch up against the stem of plants
- If using plastic, do make sure that water can reach plants
- Do watch for critters like field mice that may be using mulch for cover
- Do add organic mulches when plants are between 4 and 6 inches tall

drawing source: Virginia Cooperative Extension  ¶ 8:02 PM