Weeding is the bane of a gardener's life. If unchecked, weeds rob our grass and desirable plants of moisture, nutrients and light. In the lawn, a good stand of healthy grass, good watering practices, proper fertilization and an occasional herbicide can be used to keep them under control. In the flower bed or vegetable garden, mulching is an excellent control measure.
Mulch could be defined as any material which prevents the growth of unwanted plants and yet offers a pleasing effect to the soil surface. It should be long-lasting and not be a detriment to the soil or plants itself. Mulch can be organic or inorganic.
Inorganic mulches include black plastic, landscape cloth, ground tires, pebbles or crushed stone. Many times the plastic or cloth is covered with the stone. The plastic will hold water and limit the water reaching the desirable plants. The cloth does allow water penetration. These seem permanent; however, as dirt and organic material filter onto these and settle into the stone, weeds will simply start to grow on this new level. Pebbles and stone are heavy, expensive, hard to remove and add nothing to the soil.
There are many organic mulches. All will break down in the soil, prevent unwanted growth if applied correctly and allow moisture penetration.
Grass clippings: These are readily available, decompose rapidly, and a 2-inch layer will prevent weeds if the clippings are not full of weed seed themselves. Clippings from a lawn treated with pesticides should not be used. Grass clippings are best left on the lawn.
Hay/straw: Also available and will decompose rapidly. They will contain weed seeds. These are less ornamental than grass clippings. Light mulching on newly seeded lawns or in a vegetable garden will retain moisture on the new growth, with the weed problem dealt with in another manner.
Leaves: Similar but better than grass as the weed seeds will be minimal depending on the collection method. Certainly more ornamental if you can keep them in place. Coarse shredding may help hold them against a Kansas wind, too fine a shredding will mat down and limit water penetration. Walnut leaves contain a toxin (juglone) and should not be used. Oak and beech are highly acidic.
Raw wood chips: These are shredded trees, limbs and branches from commercial tree-trimming operations. It contains bark and wood pieces of various sizes. It may contain termites, other insects, diseases or molds. If used, it should be kept away from buildings and any plant susceptible to what it may carry. It will decompose slowly.
Prepared wood chips: Free of insects and diseases, these are available in many varieties - cypress, pine bark, cedar and cotton burr are the most common. Aesthetically, they are very effective. Some even come in dyed colors; however, this color may leach into soil. They decay slowly and generally stay in place. A 2-3 inch depth is recommended. Bulk deliveries should be compared carefully with the price of individual bags. Bulk materials are usually sold by the "yard" (cubic yard). Mulch at $3 per bag (2 cubic feet by volume) equates to $40.50 per cubic yard (27 cubic feet by volume) bulk. With the added delivery charges, the price may be comparable and the bags are easier to move about your garden.
Groundcovers: Low-growing, easily spreading plants that tend to mat will suffocate weed growth, and the aesthetic value is high. Plants such as sedum, ivy, periwinkle, pennywort, pachysandra, mondo grass and even strawberries add variety, texture and maybe more flowers. Choose Kansas-tolerant plants, and it will last for many years.
Besides weed reduction, mulch prevents loss of moisture, keeps the soil cooler in summer/warmer in winter, limits the spread of soilborne disease, inhibits soil compaction, and protects trees and shrubs from damage by lawn equipment. Be sure to remove as many weeds as possible before adding the mulch.