WHAT IS MULCH?

Mulch is a soil covering usually made of organic materials.

PROS OF MULCHING

Reduces soil erosion
Reduces weeds
Conserves moisture
Keeps plants cooler during hot weather
Prevents the spread of some disease
Keeps fruits and vegetables clean
Improves the soil if the mulch used is organic

CONS OF MULCHING

May provide a habitat for mice and small rodents
May attract slugs

HOW TO MULCH

Add a thick layer of material, 2 to 6 inches deep (depending on the density of your materials) after seedlings are 4-5 inches high. You may have to add more over the summer as it breaks down.

Do not allow it to actually touch the plants if it will be decomposing.

Remove mulch in early spring and replace it after the soil warms up.

Apply it again in late spring after weeding and water deeply first if the ground is dry. An exception -- mulch early spring vegetables (such as peas) immediately in order to keep the ground cool.

Apply winter mulches when the first frost threatens OR after the ground has frozen, depending on your area.

If you use something that is going to decompose, you should add a little fertilizer underneath it (or mix some in with the mulch) to replace the nitrogen that decomposition temporarily removes from the soil.

Do not use anything that has been treated with chemicals or fertilizers.

Avoid straw, because it can contain weed seeds and some sources tell me it can stunt plants.

Some plants prefer an acidic mulch, so I've indicated which materials you could use for those. But generally speaking, the acid level isn't so high that it makes a big difference, unless you have something that really likes alkaline soil. I can't think of anything that falls into that category. Most plants prefer a slightly acid soil anyway.

If you use a plastic mulch, it might be a good idea to install a drip system under it.

MULCHING MATERIALS

hay or straw
bark
seaweed
sawdust or wood chips (acidic)
dry grass clippings (use thin layers and dry out first)
chopped leaves or leaf mold (acidic)
ground corn cobs
well rotted manure
black plastic (can also be used to warm the soil )
shells and hulls
peat moss (acidic)
pine needles (acidic)
crushed rock, gravel, or sand
coffee grounds (acidic; good for carrots if mixed with limestone)
pieces of old carpet
aluminum foil
newspapers
tar paper

and last but not least COMPOST (my favorite LOL)