A Vocabulary Lesson for Lawn and Garden Learning

Here is a brief glossary of common landscape terms that may come in handy:

Arthropod. A phylum of animals every gardener is familiar with, it includes many-legged creatures with hard outer skeletons and jointed legs. This group includes insects; arachnids (spiders, scorpions and ticks); myriapods, such as millipedes and centipedes; and land crustaceans (sow and pill bugs) that aren't bugs at all but are related to lobsters and shrimp.

Bug. People call most insects they see "bugs." This is incorrect. A true bug is an insect from the order Hemiptera, which means half-winged. They often have scent glands that exude unpleasant odors. Several are plant pests, such as lace bug, chinch bug and squash bug.

Chemical. Most gardeners today use the term to mean synthetically derived materials, often with the implication that they are less safe to use than naturally derived pesticides and fertilizers. The truth is that they are all chemicals. Some of the most toxic synthetic organic chemicals used as insecticides were diazinon and dursban. These are materials that are no longer available for homeowner use and are not to be confused with organic matter that is added to enrich soil. Calling something an organic insecticide has nothing to do with safety. It means it was made with a carbon-based formula.

Drainage. There are two types in the landscape, surface and soil. Surface drainage means draining water away from your house by sloping the soil downhill away from walls. Soil drainage is the percolation of water into the soil as it flows away, keeping the water on your property and around your plants but away from your house.

Espalier. This is a method of training fruit trees on trellises or any network of lattice. Usually, the plant is flat against the trellis with openness between branches to allow maximum light and air to fruit. Fruiting branches are trained to grow from the main trunk in formal patterns. The term "espalier" has come to be more loosely used to mean any woody plant trained to grow on a vertical plane like a vine.

Fertilizer. Any material that supplies nutrients to plants. It can be synthetically derived, naturally derived, slow-release or water-soluble for faster availability to plants. Major nutrients are nitrogen (N), phosphorus (P) and potassium (K). Analysis is shown as N-P-K, with the percentage of each nutrient given as three numbers. A few examples you might see are 10-6-4, 18-10-5 and 5-10-5. Additionally, many trace minerals and organic materials are necessary for plants to have a healthy growth environment. Test the soil to see what is needed. If spreading dry fertilizer, use a sprinkler to move it to the roots because plants absorb fertilizer only in liquid form.

Green manure. These are plants grown for the purpose of being plowed under (incorporated into soil) over a short time to enrich the soil. Often, the plant is one that will have further benefits. Legumes like peas, clovers, vetches and alfalfas fix nitrogen in their roots that they take from the air as they grow and are an excellent way to add organic material. These young green plants decay quickly. Annual rye grass won't fix nitrogen, but it is fast germinating and can be planted late in fall and dug in after early spring growth. Leaving grass trimmings on the lawn when mowing is another way to use green manure, without the digging.

Heeling in. This is a common way to store plants through winter by protecting their roots. The most critical part of protecting hardy plants that are not in the ground is to keep roots moist by placing the plants in a trench and covering their roots with soil or mulch. Or place plants in a protected location and heap soil, compost, shredded bark or other mulch over and around their roots.

Insects. Ninety percent of all known arthropods. Many are benign and live in balance with other organisms; others are plant pests; some carry serious plant or human diseases. For example, bees and butterflies pollinate plants; elm bark beetles carry Dutch elm disease; mosquitoes transmit viruses. Many beneficial insects and other animals eat numerous insect pests, helping maintain a balance in nature.

Japanese garden. These designs include stone paths; lanterns; pagodas; sculptural elements; gates; water or symbolic water; rounded stones; rock outcroppings; conifers and other evergreens; and ground covers of moss, sweetbox, laurentia, sweet woodruff and ferns. Plants are often miniature and designs simple. Authentic Japanese gardens tell a story and must be in a space where there are no conflicting outside views.

Kitchen garden. This is an area on your property to grow fruits and vegetables that will supply exercise and fresh produce. It's best located near the kitchen, but it should also fit into your overall landscape design. A fence covered with lattice or wire with openings no larger than one inch will discourage most wildlife, as will marigolds, native tansy and lavender. Plant crops with Vole Block, a coarse slate product, mixed into your soil, because burrowing animals avoid it.

Loam. A texture of soil between fine-particle clay and coarse-textured sand. It remains friable and well drained but holds moisture, and terrestrial plants thrive in it. Loose-textured clay is described as "clay loam." Loam with many large particles in it is categorized as "sandy loam." Over many years, loam has come to be called topsoil and vice versa, but it is a particle gradation, not a description of fertility.

Mulch. A gardening term that has gone through many incarnations, it originally referred to manure, straw or leaves laid over new plant roots to hold moisture. Next, young roots were "mulched" to keep them from heaving from the ground because of continual freezing and thawing. Now it is also used as compost tilled into the soil, supplying organisms necessary to make plants thrive.

Native. This term means indigenous to the region. For plants, this means growing where they were before the settlers arrived -- 150 to 200 years ago or longer. Other authorities write "prior to European influence," which could be 400 or 500 years ago. The same question can be asked about what is native and nonnative wildlife. Balance among indigenous plants and wildlife is necessary for healthy biodiversity.

Ornamental grasses. These are grass-family plants that add aesthetics to the garden. Choose them carefully, and try to determine, if possible before planting, the growth habits of each one. Some can be quite invasive. There are some wonderful native grasses, like switchgrass, muhly grass and prairie dropseed. Hakone grass and sedges are very handsome for shade and moist sites. Most of these are not native. Note: From an invasive standpoint, remember that bamboo is in the grass family.

Soil. Soil is a mixture of live organisms and minerals that make up the outer mantle of the earth and is crucially important to our environment. We depend on it for plants to grow. It has been maintained so poorly for the past fifty years that much of it has been depleted of organic material. Replenish soil by planting green manure or digging compost into it.

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.