Anaerobic bacteria Bacteria that live or are active only in the absence of oxygen. Biennial A plant that takes 2 years to complete its life cycle. Several vegetables, including leeks and cabbage, are biennials, although they’re grown as annuals. These germinate, produce leaves, and generally are harvested the first year, but if left in the ground flower, set seed, and die the second year.
Bolt, bolting To form flowers and seeds prematurely, usually because of exposure to excess heat. This term is most often used to refer to biennial crops, such as cabbage, that flower too soon. Lettuce and spinach also commonly bolt in response to warm temperatures.
Bract Leaf- or scalelike structures borne at the base of individual flowers, flower clusters, or where a new shoot emerges on a stem. Bracts are actually modified leaves. The scales that make up an artichoke are bracts, and each bract has a morsel of edible flesh at the base. They surround the hairy “choke,” which is actually the artichoke flower.
Cell pack A lightweight plastic container typically comprised of four, six, or eight small blocks; used to grow transplants of vegetables, herbs, annuals, and other small plants.
Cloche A cover, much like a tiny greenhouse, designed to protect a plant or group of plants from cold weather. Historically, cloches were glass bell jars. Modern-day gardeners can buy paper or plastic cloches.
Compost tea A dilute liquid fertilizer made from compost.
Cover crop A crop, usually a grass or a legume, grown specifically to cover the soil surface and prevent erosion by wind or rain. Cover crops also keep raindrops from beating down on soil and compacting it; in addition, they help control weeds. Use them to fill unplanted beds or fill in around crops, or sow them between rows. Although the terms green manure and cover crop are often used interchangeably, strictly speaking, a cover crop differs from a greenmanure crop in that it is not tilled or dug into the soil.
Cotyledon Seed leaf See True leaf.
Crop rotation Altering the location where a particular crop is grown from season to season. This technique helps keep soil fertile, makes efficient use of soil nutrients, and combats crop-specific soilborne diseases. Basic principles include avoid planting a crop in the same spot it grew the year before; avoid planting crops with similar pest and disease problems in the same spot (such as crops that belong to the same plant family); and avoid planting crops with similar nutritional needs in the same spot year after year. One simple system involves grouping crops in four categories and rotating them from year to year: Fruit crops (tomatoes, peppers, eggplants, broccoli, squash, corn), followed by leaf crops (lettuce, spinach, cabbage, kale), followed by root crops (carrots, onions, potatoes), followed by legumes (peas and beans). Keeping records of what grew where is essential.
Crown The portion of a perennial where the stems and the roots meet. Asparagus is a vegetable that grows from a crown.
Cultivar A cultivated variety. A particular, distinct form of a plant that originated and is maintained in cultivation by either sexual or asexual propagation. The terms cultivar and variety are commonly used interchangeably. See also Variety.
Cuttings A portion of a stem, leaf, root, bud, or modified stem (such as a rhizome) that is separated from a parent plant, induced to form adventitious roots, and eventually grown into a new plant. Taking and rooting cuttings is a form of vegetative, or asexual, propagation that duplicates the parent plant exactly.
Dibble A small hand tool designed to poke holes in soil for seeds, seedlings, or other small plants.
Disease-resistant/tolerant A term used to describe a plant that can continue growing and bearing a crop, showing minimal or no symptoms, despite being infected by a disease organism.
Drip line The line on the soil (either real or imaginary) where rain drips to the ground from the outermost leaves of a plant.
Double digging A soil-preparation technique that deeply loosens the soil, incorporates organic matter, improves soil drainage, and also encourages plants to grow deep, wide-spreading roots.
Flat A shallow tray that holds pots. Flats can be open at the bottom to allow water to drain away, or they can hold water. The standard size is roughly 12" x 20" (30.5x50.8 cm) long.
Green manure A crop that is grown and then dug or tilled into the soil to increase soil organic matter and improve soil fertility. Green manures can be sown in fall and tilled under in spring or planted any time during the growing season. Use them to fill empty planting beds or as living mulches under row crops.
Hardening off A technique used to gradually expose seedlings, cuttings, or other plants to the conditions they will encounter outdoors in the garden.
Hot cap A small, disposable cloche (cover for an individual plant) made of waxed paper.
Inoculant A treatment for seeds that ensures the presence of certain beneficial bacteria that allow peas, beans, and other legumes to transform atmospheric nitrogen, which plants can’t use, into ammonia nitrogen, a form they can readily absorb. Inoculation increases yields and increases the amount of nitrogen left in the soil from legume-plant residue. Inoculants are crop specific, but seed companies also sell inoculant mixes that contain strains appropriate for all major crops. If you have inoculated your soil in previous years, sufficient bacteria are probably already present. Glossary
Intensive gardening Gardening systems that use a variety of techniques designed to maximize harvests by making the best use of available space. Most intensive systems grow crops in raised beds and use close spacing between individual plants. They also use succession planting and crop rotation and pay special attention to building soil and maintaining soil fertility. A well-planned, well-cared-for intensive garden can produce from four to ten times the harvest of a conventional vegetable garden planted in rows. The French intensive and biodynamic gardening systems are best known.
Legume Any member of the pea family (Fabaceae, formerly Leguminosae).
Organic gardening A method of gardening that uses natural systems and cycles to care for plants without the use of synthetic chemical pesticides, herbicides, fungicides, or fertilizers. “Feed the soil and let the soil feed the plants” is an organic-gardening adage pointing to the fact that soil-building techniques are at the heart of organic gardens. Organic gardeners use compost, animal manures, green manures, and crop rotation along with techniques such as double digging and mulching to build and maintain rich soil to support their crops. They use natural rock powders and materials such as fish emulsion to provide nutrients. Organic gardeners also foster a rich population of beneficial insects and other organisms to reduce the need for artificial pest control. They use naturally occurring substances to control insects and diseases only as a last resort.
Paper pot Also called newspaper pots, these are homemade pots made from strips of black-and-white newsprint. Two-piece molds are available to make these. Simply roll a strip of newspaper of the length and width specified around the mold and crush the bottom of the “pot” into the bottom of the mold. Pop the pot free. Fill the pots with premoistened medium and fit them snugly into a flat. To Glossary make larger pots (for large seedlings like squashes and pumpkins), simply wrap larger, thicker, strips of newspaper around cans or other containers to form your pots. Move seedlings to the garden, pot and all. There’s no need to tear off the top of the pots (see Peat pot), and they won’t wick water out of the soil.
Parasitic nematodes Also called beneficial nematodes, these are threadlike microscopic soil animals that attack other soil-dwelling organisms, including a variety of crop pests.
Parasitic wasps These beneficial insects lay eggs on the body of a host insect, such as a caterpillar, and the wasp larvae feed on the insect from within, eventually killing it.
Peat pot A container made of compressed peat moss and designed for growing seedlings. Roots easily penetrate moist peat pots, which are used to start difficult-to-transplant seeds. Seedlings can be planted right into the garden, pot and all, to minimize transplant stress. When transplanting, tear off the top of the pot to prevent the entire pot from drying out and the roots from penetrating the pot.
Pelleted or pelletized seed Seed that has been coated with inert materials to make it uniform in size and easier to handle when sowing. Crops with very small seeds, such as carrots and lettuce, often are sold as pelleted seed, which makes the seed easier to sow thinly and reduces the need to thin. Depending on the material used, pelleted seed may contain pesticides or other materials not acceptable in an organic garden, but organic pelleted seed is also available.
Perennial A plant that persists for more than 2 years. Technically, shrubs, trees, and woody vines are perennials, but gardeners and horticulturists generally use this term specifically to refer to nonwoody, or herbaceous, species.
Perlite Small white pellets of volcanic rock that have been popped like popcorn. Perlite is added to potting mixes to improve aeration. Glossary
pH A measure of the acidity or alkalinity of soil, indicated on a scale that runs from 0 to 14. Soil pH determines which nutrients can dissolve in soil water and are thus available to plants. It also influences the activity of soil organisms. A reading of 7 indicates neutral pH. Numbers below that indicate acid soil, numbers above 7 signify alkaline soil. A range near neutral (roughly 6.5 to 7.0) is considered ideal for the majority of garden plants because most nutrients are in forms plants can use. Above or below this range, certain nutrients bond with others to form compounds that are not available to plants. To determine the pH of your soil, take a soil sample and either test it using a home test kit or send it out to a lab.
Potbound The condition of a container-grown plant that has filled all the available space with roots. Potbound plants dry out much more quickly than ones that are not, and this condition eventually stunts growth. Tipping a potbound plant out of its container reveals a dense mat of roots circling the root ball; roots sticking out the bottom of the pot are also a sign of a plant that has been in the same pot too long. When planting potbound specimens, score (cut) the sides of the root ball with a knife and tease out roots to encourage them to spread into the surrounding soil.
Pregerminating Sprouting seeds before they are planted to give crops a head start on the growing season or to provide extra control over the germinating process.
Propagate, propagation To cause new plants to be produced from existing ones. Gardeners use many different techniques for propagation, including taking cuttings, dividing plants, layering, grafting, and seed sowing.
Rhizome A specialized horizontal stem that runs underground or on the surface of the soil. Since it is a stem, a rhizome contains nodes and internodes. It produces both roots and shoots at the nodes.
Season extension Lengthening the number of days a vegetable garden is productive, in both spring and fall. Season extension involves activities such as prewarming soil, starting seeds indoors, using cloches or row covers to protect transplants, protecting fullsize plants or rows of plants in fall with temporary covers such as plastic stretched over hoops, and growing crops in cold frames and greenhouses outside the usual growing season.
Sidedress A method of applying fertilizer, primarily used with row crops. To sidedress a crop, pull back any mulch that covers the soil, then spread the fertilizer along the row or around an individual plant, keeping it away from stems and leaves. Use a rake or cultivating fork to work the fertilizer into the top 2"/5 cm of soil.
Soil structure The manner in which individual soil particles clump together, or aggregate. The sizes and shapes of soil aggregates determine pore space and thus how water and air move through the soil. Ideal garden soil, that which is rich in organic matter, has plenty of aggregates that form a loose, granular, or crumblike structure. Soil structure isn’t a static characteristic: It can be improved or destroyed. Walking on soil, driving or parking cars on it, digging or disturbing it when it is too wet or too dry, or leaving it exposed (unmulched) to heavy rain all break down aggregates and compact the soil structure, making it hard for air, water, and roots to penetrate it. To improve the structure of any soil, promote the formation of aggregates by adding plenty of leaf mold, compost, or other organic matter.
Soil texture The relative proportions of sand, silt, and clay particles in soil, which determine how coarse or fine it is. Texture plays a large role in determining how well soil holds water and nutrients. Soils are classified according to the percentage of each particle they contain.
Thinning As a planting technique, thinning is the act of reducing the number of seedlings planted in a given area to allow enough room Glossary for the remaining plants to thrive. Thinning is beneficial because overcrowded seedlings can become stunted, grow more slowly, and are vulnerable to pests and diseases because of reduced air circulation. To thin a planting, pull up or cut off extra seedlings so the remaining plants are at the recommended spacing. Although destroying perfectly healthy seedlings seems like the antithesis of gardening, thinning is necessary to give the remaining plants the room they need to grow.
Topdressing An application method for fertilizer, used to enrich an entire bed of plants. To top-dress, spread the fertilizer evenly over the entire bed prior to planting and use a rake or other tool to lightly work the fertilizer into the top few inches of soil.
Train, training The process of shaping a young plant to a desired form or directing its growth so that it will climb a trellis or grow within a cage or along a garden stake.
True leaf The first leaf or leaves a seedling produces after the seed leaves (cotyledons). True leaves resemble, or somewhat resemble, the leaves of the mature plant.
Variety The definition of this term depends on who is using it. A scientist who studies plant relationships would say that a variety is a group of naturally occurring plants that are different from the species but not distinct enough to be recognized as a separate species. Plant breeders, farmers, and gardeners, however, use the terms “cultivar” and “variety” interchangeably to refer to a distinct form of a plant that originated and is maintained in cultivation by either sexual or asexual propagation.
Vermiculite A micalike mineral that is expanded at high temperatures to form lightweight, pelletlike granules that retain water but also provide good aeration when added to various potting mixes.