Mulching 101

As Spring continues to creep up on us I thought I'd touch on the do's and don't's of mulching.

Let's start by looking at different types of mulch. The 2 major types are organic and inorganic. Inorganic include various types of rock, stone, rubber and geotextile fabrics. They do not decompose and therefore don't need to be replenished often making it very low maintenance. The downside is because they don't decompose they don't add nutrients or organic materials. Organic include wood chips, pine bark or needles, bark, leaves, compost, etc Organic mulches breakdown and decompose at different rates based on material, climate, soil and other microorganisms and therefore must be replenished periodically. Organic is a much better choice if mulching around trees, plants or flowers.

The benefits of proper mulching:

• Reduces soil moisture loss

• Controls weed germination and growth

• Insulates soil and protects the roots in extreme temperatures

• Improves soil biology, aeration, structure and drainage

• Improves soil fertility as it breaks down

• Inhibits certain plant diseases

• Reduces damage to trees from weed eaters and lawn mower blight

• Improves curb appeal by giving your landscape a uniform, well-cared for look

As with anything, too much mulch can be harmful. The recommended depth is 2 to 4 inches. Unfortunately most landscapers and companies practice improper techniques and over mulch because they don't want to take the necessary time to remove the existing. You've seen these large mounds or volcanoes around trees I'm sure. If the reapplication of mulch outpaces the decomposition, buildup occurs and must be removed prior to the reapplication.

Problems associated with improper mulching:

• On areas with poor drainage deep mulch leads to excess moisture in the root zone which can stress the plant and cause root rot

• Piling mulch against the trunk or stems of trees and plants can stress stem tissue and may lead to insect or disease problems

• Some mulches can affect soil pH and may lead to nutrient deficiencies or toxic buildups

• Thick blankets of fine mulch can become matted and may reduce the penetration of water and air

• Anaerobic "sour" mulch may give off pungent odors and the acids that build up may be toxic to young plants

Proper mulching:

The choice of mulch and method of application can be important to the health of your plants. Here are a few guidelines to use when applying mulch:

• Determine whether soil drainage is adequate and if there are plants that may be affected by the type of mulch. Some plants may benefit from the use of slightly acidifying mulch, such as pine bark

• For well drained sites apply a 2 to 4 inch layer of mulch (less if poorly drained). Place mulch out to the edge of a tree's crown or beyond.

• If mulch is present, check the depth. If sufficient mulch is present break up any matted layers and refresh appearance with a rake or remove some of the existing before applying fresh mulch

• If mulch is piled against the stems or trunk of plants and trees, pull it back several inches so that the base is exposed