Mulching is man's version of what happens on the forest floor where over time plant litter accumulates and gradually decays. This mixture of dead and dying organic material forms a soft cushion around plants and protects the roots from weather extremes. The benefits of this natural process are enormous, including: the conservation of soil moisture, the reduction of weeding, the moderation of soil temperatures and, when organic mulch is used, the addition of organic matter.

A natural soil profile consists of a layer of mulch over a layer of topsoil over a layer of subsoil. As plants grow they use up the topsoil which is then replenished by the decaying mulch. Mulch is continuously added through leaf litter. In home gardens, we often eliminate the mulch layer in preference for a cultivated and tidy appearance.

This past spring, in Southern Ontario, April did not bring showers, causing exposed soil to dry out. The warm spring advanced the growth of most perennials and shrubs by almost 3 weeks. The combination of more growth and little rain depleted the soil of its moisture reserves. In cases like this, the primary reason for mulching is to conserve soil moisture and mulching could be considered an essential procedure for the survival of the garden. I threw most aesthetic considerations aside this spring and mulched with whatever I could get my hands on.

Mulch can come in many different forms, both organic and non-organic. Organic mulch has the added benefit of adding fibre and replenishing the soil, as occurs in the natural forest. Some of the most common materials for mulching are shredded bark, wood chips, cocoa hulls and stones. These are chosen mostly for their appearance. Often a landscape fabric which is made up of woven material which will allow moisture but not light to pass through it, will be placed beneath the mulch layer so that the mulch remains on the surface and doesn't get incorporated into the soil beneath. This is an effective method but does not help the soil over the long term.

Other effective mulch materials are straw, sawdust, plastic, leaves, and lawn clippings. I recently came upon baled Georgian Pine Straw. This material is an excellent mulch for beneath evergreen trees. It looks perfectly natural and blends in well with the natural leaf and cone drop from the evergreens.

An important consideration when mulching with lawn clippings, sawdust or other organic material which is not fully decomposed, is that these materials will require nitrogen to break down. Additional nitrogen should be applied or the mulch will rob the soil and the plants of the nitrogen it requires.

My garden is a mixture of styles and growing conditions and I try to use a mulching material which is most suitable for the site. In shady locations I promote a living mulch of moss and ground cover. This is encouraged by a top dressing of leaves every fall which is subsequently removed every spring. The added moisture beneath the leaves makes a perfect location for moss growth.

I had the good fortune to have an old cedar tree fall in early spring. Using my ever-handy secateurs, I clipped away the evergreen foliage and piled them on flower beds adjacent to pathways. The scent of the cedar is a pleasure to the passers by.

There is a patch of an invasive type of Miscanthus (ornamental grass) in my back garden. I put up with its aggression simply because it is such a spectacular display in the fall and I find it worth the effort to keep it contained. The spent foliage of Miscanthus is an excellent mulching material, especially in the vegetable garden where I use it to cover asparagus, strawberries and between rows. It's easy to handle and gives a tidy and planned appearance to the vegetable garden.

Whatever materials you use, mulching will help your plants and your soil. Ultimately, mulching will reduce the amount of weeding and give you more time to enjoy your garden.