Vegetable Gardening (106 page)

Some lightweight mulches, like straw or cocoa hulls, can blow around in the wind.
You may want to avoid them if you live in a windy area.

Organic mulch, which keeps the soil cool, may slow the growth and maturity of warm-season crops such as tomatoes and melons.
This cooling can be especially problematic in areas with cool summers. However in very hot-summer areas of the country, organic mulches work to keep the roots of even warm-season crops cool and healthy.

Composted manures may burn young vegetables if used as mulch because the manures vary in the amount of nitrogen they contain.
If you want to use composted manure, mix it with three times the volume of another organic mulch before applying it.

You can purchase organic mulches like shredded bark, compost, and leaf mold in bags or sometimes in bulk from nurseries and garden centers. Grass clippings, compost, and wood chips come free from your yard or garden.

Laying inorganic mulch

Inorganic mulch
includes things like plastic, landscape fabric, and believe it or not, old carpet. I explain how to use all types of inorganic mulches in the following sections.

Plastic

Plastic is the most-used inorganic mulch for vegetable gardens. Mulching with plastic (see Figure 15-4) works best when you install drip irrigation or a soaker hose underneath the plastic before planting. Otherwise, watering is difficult. (You can place the irrigation on top of the plastic, which enables you to more easily check for clogs, but you have to run individual emitters to each plant.) Plastic doesn't work well with vegetables planted very close together, such as root crops.

The color of plastic mulch you use depends on what you're growing. Some vegetables grow better with certain colored plastics. For example:

Tomatoes, eggplants, and strawberries grow best with red plastic mulch.

Melons grow well with dark green or IRT (infrared transmitting) plastic mulch.

Peppers like a silver-colored mulch.

White plastic is good for hot climates where you want to stop weeds from growing but not heat up the soil.

Black plastic is good for weed control and warming soils. It can be used on many vegetables including cucumbers and squash.

To mulch with plastic, follow these steps:

1. Purchase rolls or sheets of 2- to 4-millimeter plastic (the thicker the better).

You can find the thickness of the plastic on its label. Purchase plastic at garden centers or hardware stores, or check the appendix for sources of various colored mulches.

2. If you're using irrigation under the plastic, lay down your drip irrigation and turn it on for several hours.

Note where the wet spots are in the soil. Adjust the drip hose so water doesn't pool in certain areas, but is evenly distributed. See the earlier section on drip irrigation for more details on installing this type of watering system.