Master Rose Gardener


A quick-reference garden glossary containing all the terms you’ll need to know when growing roses.

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Acidic Soil: Soil with a pH value higher than 7.0 (pH>7) is considered alkali and can be neutralized (pH of 7 being neutral) by addition of an acid (pH<7). Soil with a pH of higher than 10 (pH>10) is considered very alkaline. Alkalinity is caused by an increase in sodium compounds or sodium carbonates, which often occur as soil minerals break down. Alkaline soil has a low water infiltration capacity which means water tends to pool or stagnate on the surface. Alkaline soils can be neutralized or acidified by the addition of organic materials such as peat moss and compost or inorganic soil amendments such as sulfur which lower the soil pH. Gypsum is often used to “condition” alkaline soil because it improves the soil structure and water infiltration capacity while replacing the sodium in the soil compounds with calcium as it breaks down.

Alkaline Soil: Soil with a pH between 7.0 and 14. To lower soil pH add sulfur.

Bare Root Stock: A plant that is prepared for packaging and shipping by removing all the soil around its roots.

Biological Pest Control: Using living organisms such as beneficial insects or parasites to destroy garden pests. Visit our page on beneficial insects to learn more.

Chlorosis: A yellowing or blanching of the leaves due to lack of chlorophyll, nutrient deficiencies or disease.

Companion Planting: The sowing of seeds in the garden in such a way that plants help each other grow instead of competing against each other.

Compost: The end product of the decomposition of organic matter and biodegradable materials by aerobic and anaerobic microbes is known generally as compost. Compost is nutrient rich since during the decomposition process the larger organic compounds are broken down into their basic elemental particles that are easier for plants and other organisms to absorb. Compost serves as a great growing medium for agricultural and horticultural purposes as well as a soil conditioner. This dark brown to black soil/mulch can be easily made in the kitchen or back yard in a compost container or the more traditional pile form. Click on our composting guide for more information.

Cuttings: A technique for propagating plants in which a piece of the source plant is cut away and then placed in a growing medium. The cutting becomes independent of the source plant.

Dead Heading: Cutting off dead or dying flowers to encourage further blooms by preventing the setting of seeds.

Drip Irrigation: A method of watering plants where small tubes or hoses are used to deliver water to the plant’s roots. The water is not sprayed into the air, so the plant’s leaves remain dry, which reduces fungal diseases.

Fertilizer: An organic or synthetic material added to the soil or the plant, that is important for its nutrient value (see A Gardener’s Guide to Fertilizers).

Floribunda Roses: Any of several hybrid roses bearing numerous single or double flowers. Plants are hardier and bushier than most roses.

Frost Date: The average yearly date that the last or first frost of the year occurs.

Fungal Disease: Respiratory and skin diseases resulting from inhalation or direct contact with fungal spores in soil and compost. Overly wet soil (40% water) and compost are the usual causes of respiratory fungal diseases such as “farmers’ lung.” Symptoms usually occur 4-6 hours after exposure and are flu-like with a high fever and aches lasting for 12 hours or more. Skin infection may result in rashes and sores.s

Grandiflora Roses: The perfect cut flower, Grandiflora roses are a cross between Hybrid Teas and Floribundas. They are round, bushy plants that grow 3 to 6 feet tall.

Growing Media: The material used to grow a plant or germinate seeds.

Growth Bud: A small, raised mark on a stem or branch containing an undeveloped leaf, flower, or shoot.

Hardening Off: The process of acclimatizing plants grown under protection, in the greenhouse for example, to cooler conditions outdoors. Learn more about hardening off here.

Heritage Roses: Antique or old roses that originated in the mid 19th century or earlier.

Hybrid Tea Roses: Most often sold in floral shops, hybrid tea roses are bred for their beautiful large blooms. Plants grow up to 3 feet tall and usually produce one bloom on a long stem.

Integrated Pest Management (IPM): An effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices. IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment. This information, in combination with available pest control methods, is used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment.

Miniature Roses: A diverse class of roses that are smaller than other varieties. They tend to be hardy and are often grown in containers.

Mulch: A soil covering used in gardening and agriculture to protect soil from the extremes of weather and climate by helping conserve soil moisture and moderating temperatures. Mulch helps soil retain water from rainfall and heat absorbed during daylight. It also protects soil against direct sunlight therefore keeping soil moist and cool during the hot summer months. Weed prevention is a major use for mulch. It both blocks sunlight to unwelcome weeds and smothers the seeds before they start. Mulch is also great for erosion prevention and protecting soil from the damaging aspects of heavy rains. Common materials used for mulch are: hay, straw, grass clippings, bark, sawdust, wood chips, newspaper, and cardboard. Rocks, gravel and plastic are also often used as mulch. If compost is used as mulch, it is necessary that it is fully composted and that all weed seeds have been killed; otherwise, it will actually contribute more weeds to the area.

N-P-K: Stands for Nitrogen, Phosphorus, and Potassium (aka potash) the macronutrients necessary for plants to survive and grow. Usually listed on fertilizers and soil amendments with a number, for example 7-9-5, representing the percentage by weight of each nutrient contained in the product. Nitrogen is the macronutrient necessary for vegetative growth above ground. Nitrogen, the most important macronutrient, promotes healthy stem and leaf growth and provides for rich dark green foliage. Phosphorus is the second most important macronutrient and is vital to root growth, fruit and flower development, and disease prevention. Potassium is important for strong, healthy plants. It contributes to disease resistance and protects plants from cold as well as water loss during periods of heat and drought.

pH: The measure of the acidity or alkalinity of a substance or solution. Technically pH measures the activity of dissolved hydrogen within a substance. pH is a relative measurement with “pure” water being neutral at pH 7.0. A pH lower than 7.0 is considered acidic and a pH higher than 7.0 is considered alkaline or basic. Adding an alkaline to an acidic substance will raise its pH making it more neutral or alkaline. An acid added to an alkaline substance will lower the pH and make the substance more neutral or acidic.

Photosynthesis: The process in plants by which carbohydrates are produced from carbon dioxide and water using light as an energy source.

Rose Hips: The bright reddish-orange fruit of the rose plant – they remain after the petals fall off.

Season Extender: Techniques and equipment used to extend the growing season in both spring and fall. Examples include greenhouses, cold frames, hotbeds, row covers, and products such as Wall O’ Waters.

Soil Amendment: Any material added to soil to improve or change its characteristics. Soil amendments are utilized when physical properties such as structure, aeration, nutrient and water retention, and drainage need improvement. The main function of soil amendments is to provide a better environment for the roots so they can grow and absorb nutrients more easily. Compost is a common soil amendment as it improves soil structure and nutrients. Other common soil amendments are greensand, blood meal, bone meal, alfalfa meal, glacial rock dust, and various fertilizers.

Suckers: A shoot that sprouts from the roots or trunk of a tree, shrub or bush and drains its energy.

Topdressing: Application of a thin layer soil mix or compost to a lawn or garden. Topdressing improves soil quality gradually as each successive layer builds upon the last. It is a method used to even out bumpy or uneven lawns and stimulates grass to grow new roots resulting in a thicker lawn cover. Topdressing is similar to sheet composting in application except that the material used is fully decomposed.

Transplanting: Shifting of a plant from one soil or growth medium to another.

Weed: Any plant that is unwanted or considered to be a nuisance. To many people weeds are simply an eyesore while to others they are problematic because they block sunlight and rob other plants of nutrients.

Zone: Plant hardiness regions determined by the average annual minimum temperature.

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