MULCHING FOR YOUR GARDENS HEALTH

Mulching involves placing a layer of material around the base of plants to stabilize temperature, conserve moisture, and control weeds. The insulating qualities provided by the mulch will help protect roots from heat stress. This results in stronger, healthier plants. With lower water evaporation rates, a consistently adequate soil moisture supply is available, and nutrients are more easily obtained by plants. This helps prevent blossom end rot on tomatoes and other plant diseases related to lack of nutrients.

For vegetables such as tomatoes, peppers, and squashes, mulch acts as a barrier between the soil and the fruit, keeping vegetables clean and dry, and lessening the risk of spoilage. Weeds are also controlled by a covering of mulch, resulting in less competition for water and nutrients by the vegetables, and fewer back problems for the gardener.

MULCH MATERIALS

Leaf litter, grass clippings, compost, and peat moss are biodegradable materials readily available to most gardeners for use as mulch. Peat moss tends to form an impermeable mat when used on its own, and can act as a sponge, preventing water from passing through to the soil. It is best used sparingly in conjunction with other mulching materials.

Grass clippings and leaf litter are good mulches, as long as they are weed free, and are not fresh and green. Fresh vegetation can heat the soil as it is decomposing, and deplete the soil of nitrogen more than mulch that is partially broken down. Do not use grass clippings from a lawn that had a weed killer applied within the last two mowings.

Older grass clippings and leaves laid down as a mulch can also cause a temporary nitrogen deficiency, as soil microorganisms pull from the soil the nitrogen they need to break down the vegetation. Once the mulch is broken down, the nitrogen will be released to the soil, but to avoid a temporary deficiency, some extra nitrogen should be provided. Compost used as a mulch will not present this problem.

Some well-rotted manure or compost can be mixed with grass clippings and leaves in a one to ten proportion before it is added to the garden, or a fertilizer such as 16-20-0 can be sprinkled over the top of the mulch after it is added to the garden at rates of 2 pounds per 1000 square feet.

Mulch should be laid in the garden in early July for warm weather vegetables such as tomatoes, peppers, and vine crops. By this time, the soil has had adequate time to warm up, and the plants have had a chance to become established. If the soil in your garden has a sandy texture, it will warm up to favourable temperatures more rapidly in spring, so mulch can be applied two weeks earlier. However, if the soil is a heavy clay, mid-July is the best time for mulching warm season vegetables.

For cooler season crops such as peas, cabbage, broccoli and cauliflower, mulching can begin two weeks earlier than with warm season crops, adjusted to the type of soil you have in your garden.

When it is time to mulch, the garden should be watered well before placing a three to four inch depth of grass clippings and leaves around the bases of plants. Liberal amounts of mulch are necessary to insulate the soil root zone and lower evaporation rates. As the leaves break down, add more material to the top to maintain the same depth throughout the growing season. This will ensure that your vegetable roots will remain relatively cool with a consistent supply of moisture through the hot summer days. After harvest, the mulch can be worked into the garden to supply the soil with organic matter. With its many attributes, mulching is a practice well worth trying for the back yard gardener.