By Joel M. Lerner
Saturday, February 16, 2008; F03

The green movement has grown dramatically in recent years, creating its own vocabulary to describe a variety of products and practices that purportedly are healthier for people and the environment. If you want to go green in your garden, here is a glossary of common terms you will encounter:

Biodegradability

The ability of organic material to be broken down by bacteria, worms, fungi, insects and other means. The end product is compost.

Biodiversity

The coexistence of a wide variety of plants and animals. Invasive species can disrupt this balance.

Bioremediation

Similar in concept to biodegradability, except that this process can apply to a broader range of substances, including oil, tires, plastic and pressure-treated lumber.

Chemical

The antithesis of green, though the term "chemical" can be confusing because all matter is made up of chemicals -- organic or inorganic. Compost, for example, has a chemical formula. Through common gardening usage, "chemical" has come to refer primarily to man-made fertilizer and pesticides that, when used to excess, are bad for the environment.

Chlorophyll

A pigment that makes leaves green and, when combined with sunshine, is responsible for plant life.

Ecology

The study of the interactions of organisms in their environments and the practices we can employ to ensure biological health in the world.

Green roof

A roof that is partially or completely covered with vegetation. Traditionally they were made of mud; weeds grew on the mud and created sod that helped keep houses warm or cool. Given today's building materials, codes, regulations and urban atmospheres, however, a firm understanding of the subject is crucial before creating a yard on your roof.

IPM

Integrated pest management, a strategy that aims to use the least pesticide necessary.

Native plants

Those that are indigenous to a particular region and have evolved with the wildlife there.

Natural

The natural garden requires less work than tightly clipped hedges and manicured lawns. There is no such thing as a maintenance-free garden, but this style will grow full with little work. Cut back perennials once a year, prune woody shrubs only when they're growing where you don't want them, mulch, and enjoy.

Organic

Any carbon-containing material that is or was alive. Organic material is crucial to soil health and is often the substance that makes the difference between subsoil and topsoil. Today the term primarily concerns food labeling.

Permaculture

Virtually synonymous with sustainable landscaping, permaculture is a collection of activities each of us can do in our living spaces that, taken cumulatively, can make a difference. Under this system, resources seldom leave the property. Every element is reused or generated on-site. Wastewater is filtered through plants and used to irrigate vegetables. Organic material is composted. Electricity is generated. Water can be pumped by wind.

Rain garden

A saucer-shaped depression, three to six inches deep, that is planted with native grasses and perennials. The hollowed area and plants collect rain and allow it to slowly percolate into the ground instead of running off into our streams and rivers. See what's being done locally by Pepco at http://www.potomacriver.org/arbc/rgphotos.htm.

Sustainable

Supporting our planet's needs by conserving our water, air, soil, forests, lakes and oceans.

Wetlands

Terrain that stays wet or floods regularly. Wetlands feed aquifers that supply us with drinking water. It's important that they are protected from fertilizer and pesticide runoff, as water is a basic need for all plants and animals and a crucial habitat for both.

Wetlands remediation

In most jurisdictions, the replanting of swampy places with native plants after they are disturbed by excavation or construction. The goal is to restore the wetlands' ability to handle runoff and recharge aquifers.

Wildflower meadow

Usually a mix of grasses, annuals and perennials growing in open, sunny fields, meadows can be created to mimic those found in nature. Plants are usually native. Generally started from seed, they appear more natural at maturity. They require good timing (sow in summer) and lots of patience (at least three years) for a balanced planting that will return annually.

Wildlife habitats

Food, water and shelter are necessities for wildlife to remain in the garden. Learn the needs of the types of wildlife you wish to attract. Birds, bees, butterflies, toads, turtles, snakes, rabbits and chipmunks, deer and foxes have their own needs.

Joel M. Lerner is president of Environmental Design in Capitol View Park, Md. E-mail or contact him through his Web site, http://www.gardenlerner.com.