Glossary of Terms Guide to gardening terms
Accelerator - Any substance used to assist the decomposition of organic matter in the preparation of garden compost.
Acid soil - Soil with a pH measure below 7, also called sour soil. Most soils in the eastern third of the United States, Canada and the West Coast are naturally acid.
Aeration - Introduction of air to compacted soil by mechanically removing plugs of topsoil. Aeration helps oxygen, water, fertilizer and organic matter to reach roots. Also, incorporating air into compost by turning the pile. Incorporating air into compost helps the plant material decompose more quickly.
Agronomy - Applied agricultural science dealing with rural economy and husbandry. In recent years it has concentrated mainly in the theory and practice of crop production and soil management.
Alkaline soil - Soils in central Pa. where limestone is present are usually alkaline. Acidic loving plants (Ericaceous Plants) such as Rhododendron and Mountain Laurel, will need soil supplements to establish themselves successfully.
Amendments - Organic or mineral materials, such as peat moss, compost, perlite, to name a few that are used to improve the soil.
Annual - A plant that germinates, grows, flowers, produces seed and dies in the course of a single growing season.
Architectural development plan - This is a comprehensive plan that includes proposed and existing landscape features in conjunction with a new building or addition to an existing building.
Bid - The proposed price to perform the work outlined on an accompanying plan or document. Also referred to as a quote.
Biennial - A plant sown one year to flower or fruit the next, then dying or being discarded. Many vegetables are biennial, but are treated as annuals and harvested in their first year before they have flowered.
Bio-swale - A swale area, sometimes called a "ditch," but one that is designed to slow stormwater runoff and filter that runoff through a matrix of plants that thrive in wet conditions to improve water quality and prevent soil erosion.
Certified Landscape Technician (CLT) - This term recently changed to Landscape Industry Certified Technician (see below). This person has passed a national "hands-on" test administered by the Associated Landscape Contractors of America (ALCA), which is administered in Pennsylvania by the Pennsylvania Landscape & Nursery Association (PLNA). The test requires knowledge in landscape installation, landscape maintenance and/or irrigation. Re-certification every three years, assures their customers that they remain current with national industry standards.
Compost - Humus made by decomposing vegetative matter in a compost bin or pile.
Contract - It is a signed document that outlines the work to be performed by the installer and a schedule of payments to be made by the customer, and the circumstances under which the work will be done and payments will be made.
Cool-season grasses - Grasses that thrive in northern areas, including Canada, and in high elevations in the South, such as blue grass or fescue.
Cross-pollination - The transfer of pollen from one plant variety to another.
Crown - The part of a plant where the roots and stem meet, usually at soil level.
Cultivars - A cultivated variety of plant, often bred for a desired trait, such as pest or disease resistance, flower color, fruit color and/or persistence, habit/size, foliage color/texture, etc..
Damping-off - A fungal disease that attacks seedlings, causing them to shrivel at the base. Damping-off is brought on by one of several fungi, including Pythium and Rhizoctonia, which thrive in stagnant air and high humidity.
Deadhead - To remove old flowers to prevent seedpods from forming.
Design-build firm - A company that has Landscape Architects and/or Landscape Designers as well as Landscape Contractors on the staff. They work with the property owner to develop a landscape plan and then implement the plan themselves. If the scope of the work is extensive, they may hire outside specialty contractors to perform specialized tasks such as asphalt paving or swimming pool installation.
Dormant - Alive but in a state of suspended animation until all conditions are right for growth.
Drainage - The movement of water through the soil. With good drainage, water disappears from a planting hole in less than a few hours. If water remains standing overnight, drainage is poor.
Drip irrigation - This is the practice of applying water slowly through various types of pipes, tubes or specialized hoses. The simplest form would be the use of soaker hoses commonly found in garden centers. More sophisticated systems can be installed by homeowners or irrigation contractors that are preset to go on by a computer.
Edging - A shallow trench or physical barrier of metal, wood, brick or synthetic material used to define the border between lawn turf and another area, such as paving or a flower bed.
Endophytes - Fungi that live in some grasses (called endophytic) and make them harmful or deadly to a variety of above ground grass-eating insects.
Estimate - The price to perform work that has been agreed to in principal. There may be no plan associated with an estimate. There may be unknown circumstances (such as physical underground features that cannot be accurately determined without extensive — and often expensive — exploration). The final price can vary according to these and/or other circumstances.
Exposure - The intensity, duration and variation in sun, wind and temperature that characterize any particular lawn or planting site.
Frost heave, frost heaving - A disturbance or uplift of soil, pavement or plants caused by moisture in the soil freezing and expanding.
Full Shade - A site that receives no direct sun during the growing season.
Full Sun - A site that receives at least eight hours of direct sun each day during the growing season.
Grade - The degree and direction of slope on an area of ground.
Green roof - A roof that is specially designed to hold a matrix of plants instead of having traditional roofing materials, such as asphalt shingles. Green roofs reduce stormwater runoff, cool in the summer, insulate in the winter and provide a striking design contrast to traditional roofs.
Ground cover - A plant, such as ivy, Loire or juniper, used to cover the soil and form a continuous low mass of foliage. Often used as a substitute for turf grass, especially in shade, embankments, or other areas where turf grasses don't perform well or are difficult to maintain.
Hardiness - A plant's ability to survive the winter without protection from the cold. The temperature range in which a plant will grow and thrive. Cold is usually the main consideration; however, heat and humidity can also cause plants to fail.
Hardiness zone - Typically, the regions where the coldest winter temperatures occur will determine the zone, such as 0 to 10 (Zone 6, according to the USDA Plant Hardiness Zone Map). More recently, the heat and humidity are being considered as equally limiting and upper hardiness zones are beginning to be listed as well. Additionally, it should be noted that Zone 7 on the West Coast and Zone 7 on the East Coast are not the same climates due to humidity, rainfall, number of days below freezing, cloud cover, etc.
Hardscaping - The installation of non-plant features in the landscape. These include features such as: walls, walks, driveways, curbs, patios, pools, tennis courts, etc.
Heat zone - A region determined by the average annual number of days its temperatures climb above 86 degrees.
Herbicide - A chemical used to kill plants. Permanent herbicides, pre-emergents, are used to kill weed seeds as they sprout and thus to prevent weed growth. Post emergent herbicides kill plants that are already growing.
Horticulture - The use and study all types of plants.
Horticulturist - Someone who has extensive knowledge of plants, their care and their requirements for survival.
Humus - Thoroughly decayed organic matter. Added to lawns gardens or beds, it will increase a soil's water-holding capacity, improve aeration and support beneficial microbial life in the soil.
Interiorscaping - The installation of plants and other features in enclosed spaces that are not subject to outdoor weather.
Invasive species - A species that by its establishment and dominance can cause widespread harm to public health, an ecological system or an economic system.
Irrigation - This is the practice of applying supplemental water to plant and lawn areas. New regulations in most states require the computer that automatically turns on sprinklers or drip emitters to apply water only as needed based on recent rains. An exterior water meter sends the recent rainfall totals to the computer to help monitor the water needed so as not to waste water that does not need to be applied. It also helps the plants to prevent them from getting too much water that can often lead to disease and death.
Landscape - This is 'the lay of the land' which includes plants and other physical features such as lawn or meadow areas, waterways, pavement, utilities, structures, etc. Mistakenly used to refer only to planting in many instances.
Landscape architect - A legal term established by the state, this person has 4 or 5 years of education in an accredited college followed by 3 or 4 years apprenticeship under a registered landscape architect (RLA). Subsequently they will have passed a licensing exam. Jobs would often be larger in scope than those performed by a Landscape Designer (described below), and could incorporate large scale master planning and the design drawings and specifications to accomplish the plan. Landscape Architectural design firms usually put out plans for bid by independent Landscape Contractors.
Landscape contractor - A firm that implements landscape plans prepared by Landscape Architects or Landscape Designers. They may bid on a job or work with the designer throughout the design process. Depending on their in-house expertise, they may hire sub-contractors to perform specialized tasks such as masonry, paving, carpentry, etc.
Landscape design-build firm - Landscape Design-Build firms usually perform the work themselves using their own employees, although the use of outside sub-contractors is not uncommon. Landscape Architects and/or Landscape Designers are usually employed to do the designing. Often they are the firm's principals.
Landscape designer - A person who has education and/or training in the design of residential and commercial properties. Jobs can include plantings, walkways, walls, water features, landscape lighting, fences, and other similar features. LDs are often employed by a design-build firm that does most the work themselves. They may contract some tasks to other companies. They may have a Landscape Architecture degree from an accredited college. They are not registered Landscape Architects.
Landscape fabric - A synthetic fabric that is usually water-permeable, it is spread under paths or mulch to serve as a weed barrier.
Landscape Industry Certified Technician - This person has passed a national "hands-on" test administered in Pennsylvania by the Pennsylvania Landscape & Nursery Association (PLNA). The test requires knowledge in landscape installation, landscape maintenance and/or irrigation. Re-certification every two years, assures their customers that they remain current with national industry standards.
Landscape Industry Certified Manager - This person has passed a written examination adminsiter by the Professional Landcare Network (PLANET). The exam covers a broad range of issues realted to management of a landscape contracting company.
Landscape maintenance contractor - An individual or firm that maintains landscapes in ways such as the following:
1. Lawn mowing and fertilizing,
2. Shrub and tree pruning,
3. Fertilizing and mulching of planting beds
4. Insect control on lawns and plants
1. It is different from, and may be part of, an Architectural Development Plan
2. This is a series of drawings that is necessary for the Landscape Contractor to complete the landscape portions of a project. There are often individual sheets for each of the specific landscape tasks, which could include: earthwork (cut and fill); paving for vehicular travel; pedestrian walks; retaining structures; building plans and locations; planting; etc. (Similarly, an Architectural Plan would have separate sheets for the plumbing, heating & cooling, electrical, interior finishes, etc.)
3. This term is often (and mistakenly) used to refer solely to the Planting portion of a job.
Landscape trades - The following are job categories of people who help shape the land and/or install or maintain plants either physically or through the design process: Civil Engineer, Excavation Contractor, Horticulturist, Landscape Architect, Landscape Contractor, Landscape Designer, Landscape Maintenance Contractor, Masonry Contractor, Nurseryman/Nurseryperson, Swimming Pool Contractor.
Landscaping - A term that is very comprehensive and sometimes misleading. It is usually used to indicate only planting, instead of planting in conjunction with the installation other landscape features — walks, walls, patios, decks, etc.
Lawn restoration - Improving a lawn by a combination of fertilization, aeration, turf plug planting, and/or seeding without killing or removing all existing turf.
Lime, limestone - A white or grayish mineral compound used to reduce soil acidity and to supply calcium for plant growth.
Loam - An ideal soil type for growing, loam contains an equal balance of sand, silt and clay. It has benefits of both clay and sand in that it will hold moisture and organic compounds, yet it is porous and will drain well.
Masonry contractor - An individual or firm that installs and/or repairs walks, walls, etc. of brick, stone, concrete pavers, etc. This work might be performed in whole or in part by a Landscape Contractor as well.
Mass planting - Filling an area with one or a few kinds of plants, such as ground covers, spaced closely together. Often planted to create a bold, dramatic effect or to reduce lawn maintenance.
Master Gardener - They are community volunteers trained by county agricultural extension agents. Once they complete their training, Master Gardeners begin volunteer service. They cooperate with service agencies and community groups on a wide range of gardening projects. They often provide hands-on training through demonstrations for home gardeners, clubs, and other organizations.
Microclimate - Conditions of sun, shade, exposure, wind, drainage and other factors that affect plant growth at any particular site.
Mulch - A layer of bark, peat moss, compost, shredded leaves, hay or straw, lawn clippings, gravel, paper, plastic or other material spread over the soil around the base of plants. During the growing season, mulch can help retard evaporation, inhibit weeds and moderate soil temperature. In the winter, mulch of evergreen boughs, coarse hay or leaves is used to protect plants from freezing.
Organic matter- Plant and animal residues, such as leaves, trimmings and manure, in various stages of decomposition.
Overseeding - Spreading seed over established turf that has been prepared for restoration.
Native plants - North American plants which grew in an ecosystem (or ecosystems) prior to 1492 AD. Pennsylvania native plants were a part of the climax coniferous forest ecosystems of the pre-Columbian mid Atlantic region.
Node - A joint in plants from which leaves emerge.
Nutrients - Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron and other elements needed by growing plants and supplied by minerals and organic matter in soil and by fertilizers.
Nursery trades - The following are job categories of people who work with ornamental plants: Florist, Grower (of nursery crops), Horticulturist, Landscape Contractor, Landscape Designer, Landscape Maintenance Contractor, Nurseryman/Nurseryperson, Plantsman/Plantsperson.
Nurseryman/Nurseryperson - A person who has a job in one of the nursery trades.
Ornamental horticulture - The study of plants that are generally considered, by most horticulturists, to create beauty in a wide variety of circumstances. Plants commonly known as vegetables or weeds can, in certain circumstances, be ornamental, but are generally not thought of as being plants that are generally used for ornamental purposes.
Pennsylvania Certified Horticulturist (PCH) - This person has passed a test administered by the Pennsylvania Landscapeand Nursery Association. This person is also accredited by the laws of the Commonwealth of Pennsylvania to help assure the public that the PCH has extensive knowledge of the Landscape and Nursery Trades. Many other states have similar programs and licensing procedures.
Perennial - A plant that lives more than two years or three seasons and normally flowers annually. Many die down during the winter but the roots are unaffected by frost and new growth appears as the weather improves and the temperature rises.
Plugs - Young perennials or grasses used to cover large areas of beds or lawns; so-called because they are "plugged" into small holes drilled or dug into the soil.
Pressure-treated lumber - Lumber treated under high pressure with chemicals that protect it from decay.
Proposal - The proposed contract between the installer and the client. It outlines the work and timing of that work to be performed by the installer and a schedule of payments to be made by the prospective client. It becomes a contract between the installer and the client when signed by both parties.
Quote - The proposed price to perform the work outlined on an accompanying plan or document. Also referred to as a bid.
Rain garden - A garden that is designed to capture stormwater and infiltrate it to groundwater. A rain garden's soils are usually designed to support plant life, but encourage perolation of storm water to ground water. Plants for rain gardens are chosen for their ability to thrive in wet conditions, but that can adapt to dry periods.
Retaining Wall - A wall built to stabilize a slope and keep soil from sliding or eroding downhill.
Rhizomes - Underground runners of some types of plants that extend laterally to create new plants.
Seedling - A young plant grown from seed.
Selective pruning - Using pruning shears to remove or cut back the branches of woody plants.
Sod - Carpet like sheets of turf about 3/4 inch think, 1-1/2 feet wide and approx. 6 feet long. Sheets may be laid over prepared soil to establish new lawns. Many types of grasses are available. More recently, wildflower sod is being grown for rapid establishment of meadows.
Sprigs - Cut-up lengths of rhizomes or stolons (above and underground runners) that can be broadcast and pressed into the soil to establish new lawns.
Stolons - Aboveground runners from which some grasses, particularly warm season varieties, spread.
Subsoil - A light-colored soil layer of varying consistenciesfound beneath the topsoil. It contains little or no humus.
Sustainable landscape - A landscape that is designed and installed to minimize the use of non-renewal resources, reduce energy comsumption, reduce stormwater runoff, improve water quality, recharge groundwater, improve air quality, sequester carbon, improve human health and well-being, and increase the economic value of the property and surrounding area.
Thatch - A mat like buildup of grass roots and stems (but not of grass blade clippings) that if too thick can inhibit healthy growth.
Tillers - Aboveground sideshoots of some types of grass plants.
Trickle irrigation - See Drip Irrigation
Warm-season grasses - Grasses that grow best in southern regions, thriving in the heat of summer, such as Bermuda or zoysia.
Weed - Any undesirable plant or grass species; any plant growing where you don't want it.
Xeriscaping - The use and installation of plants that, once established, require little or no supplemental water to thrive. These are plants that are often found in desert areas, however, there are numerous indigenous plants to the northeast USA that require minimal moisture to perform well during drought years. Xeriscaping is a trademark of the Denver Water District.