Step 7 - Keep Down Weeds - Illinois Vegetable Garden Guide - University of Illinois Extension

Step 7 - Keep Down Weeds

It is important to control weeds in your garden because they compete with your vegetables for water and nutrients. Also weeds often harbor insects and diseases. The best time to attack weeds is just as they appear on the soil surface. If allowed to grow too large, weeds will shade your vegetables, causing your crop to grow poorly.

Cultivation by hoe or cultivator is the method most commonly used in gardens. The main purpose of cultivation is weed control, although on some Illinois soils cultivation may be needed early in the season to loosen the soil and aerate the roots better.

Begin cultivation as soon as weeds begin to sprout. Repeat cultivations as weeds appear. Do not work the soil if it is too wet. Roots of many vegetables are near the soil surface and can be damaged easily by a hoe or cultivator if you are not careful when cultivating. Shallow cultivation is desirable near plants and later in the season.

Mulching is covering the soil around your vegetables with protective material. Most vegetables benefit from mulching. Tomatoes, cucumbers, melons, beans, and potatoes are some of the crops for which it is most practical to mulch. Besides controlling weeds, the mulch will save moisture, keep the soil temperature more even, and keep the fruits clean.

Leaves, grass clippings, peat moss, sawdust, ground corncobs, straw, foil, paper, and black plastic can all be used for mulches.

Organic mulches, such as sawdust, leaves, straw, or corncobs, should be placed on the soil after the plant is well established; usually this is just after the first cultivation. Spread the material evenly over the soil between the rows and around the plants. Mulches like leaves or straw are usually applied 3 or 4 inches deep.

If you do not apply nitrogen with mulch, be on the alert for a nitrogen deficiency, shown by light green or yellowish leaves.

Chemical weed control is available through the use of herbicides, but using them in the small garden is not a good practice because different vegetables vary in their tolerance to herbicides.  Since your garden will have many different types of vegetables in many stages of growth, it can be risky to use such products.  Drift from herbicides used near a garden may damage your crop and render the vegetables not usable.  If you decide that herbicides should be used, consult your local extension office or garden center for recommended products.