Abscission: The natural dropping of leaves and flowers from a  plant.

 Acidic Soil: A soil with a pH of less than 6.5

Adventitious: A plant that forms its’ characteristics in unusual locations, for example roots growing from leaves or above ground stems.

 Alkaline Soil: A soil with a pH of more than 7.3

 Annual: A plant that grows from seed or cutting that flowers, produces seeds or fruit and dies all within one season.



 Bare-root: A plant or tree that is sold with no soily root ball, the roots are completely exposed. The plant is dormant.

 Basal Shoot: The new growth that appears near ground level.

 Biennial: A plant that grows from a seed producing leaves and stems the first year and flowers/fruit the second year.

 Biennial Bearing: Refers to fruit trees that bear fruit heavily one year and then nearly no production the next year.



Cambium: The thin ring of tissue within a stem on the outer layer of a branch or trunk. This layer continually forms water and nutrient conducting vessels. If these are severed completely the plant or tree will die.

 Cane: A long slender shoot that rises from the crown of the plant, such as raspberries.

 Canker: A diseased part of a tree or branch, it’s usually blackened, discolored and misshapen.

 Central Leader: The main vertical leader forming the center of the tree.

 Chlorosis: The yellowing of leaves due to loss of or breakdown of chlorophyll. This may result from lack of nutrients, poor growing environment, disease or an insect infestation.

 Chilling Requirement: Some plants need to have a certain number of cold days below a temperature of about 45 degree F. in order for blooms to open. Trees, perennial flowers and bulbs that are native to cold climates usually have a chilling requirement printed on the label. (also known as Vernalization)

Climber: A woody plant that has the ability to attach itself  or be tied to an upright structure.

 Cold Frame: Is a dome shape structure that protects the plants, but is only for light frost protection in the spring.

Conifer: A family of trees and woody plants, often evergreens that produce cones.

Cotyledon: The first two leaves that emerge from a seed, these leaves are different than the ones the plant will grow after that.

 Crown: The lowest part of a plant where the branches meet the base of the plant. This area is best kept above the soil line. On a herbaceous plant it’s spot where the roots grow downward and the shoots grow upwards.

 Cultivar: A cultivated variety of any plant, abbreviation “CV”. It’s a hybrid word made from the combination of “cultivated”  and “variety”.



Deadheading: The removal of faded flowers from the plant.

 Deciduous: Refers to broadleaf trees and shrubs that lose their leaves in fall.

Diatomaceous Earth: A natural insecticide composed of silicon dioxide from the crushed decomposed shells of “diatoms” (tiny sea creatures) DE acts like ground up glass and cuts into the waxy coating of insects which causes them to dry out and die.

Disbudding: The removal of small, side flower buds to achieve a larger size of the main flowers.

 Dormancy: The period of time where the plant is dormant, or asleep.

 Dormant oil: Horticultural oil sprayed on deciduous trees or shrubs in winter to kill over-wintering insects and insect eggs in and on the bark.

 Dwarf Bush: A tree pruned to give 1.5 to 2 feet of clear stem.




 Espalier: The method of pruning and training a tree (usually fruit trees but sometimes ornamental ones as well) to be flat against a wall or fence.

The branches are trained horizontally with a short trunk.



 F1 Hybrid: The first generation of offspring that results from the breeding of two closely related plants. Does not breed true.

 F2 Hybrid: The plant that’s produced by crossing two F1 hybrids. Doesn’t breed true either, and is less vigorous than F1.

 Fan: Same as described above with espalier, but the branches are trained to radiate out in a “spread open hand” shape, and the center one going straight up.

 Foliar Feed: A fertilizer specifically designed for spraying on the leaves of a plant for direct absorption.

Forced Bulbs: A term used to describe the way plants are “forced” to bloom at a time that is not their normal schedule. This can be done by controlling the temperature, light or both.

 Friable Soil: Crumbly.

 Frost Pocket: A trapped area of cold air in the winter wherein the “half-hardy” plants are in greater danger.



 Gall: Is an abnormal growth on leaves and branches and it often white colored. Azalea is susceptible as are Rhododendron.

 Graft: The joining of two different plants to create one new plant with the roots of one and the greens of the other.

 Girdling root: A root that has grown around the base of the tree trunk above the root-ball during it’s first couple of years. This root must be removed,  it will get larger and strangle the tree as it grows.



 Half-Hardy: A plant that will die if the freezing point falls below zero degrees Celsius.

Hardening Off:  The process of acclimating seedlings from the indoors to the outdoors.

 Hardiness: An individual plants’ ability to survive cold temperatures.

 Hardy: A plant that will survive the winter without frost protection.

 Herbaceous Plant: A plant that does not form hard woody stems, and will die back to the ground each winter. Such as Hosta and Dicentra

Hotbeds: Cold frames that are equipped with heating systems.

 Hybrid: Plants whose parents are genetically distinct.



Intermediate Plant Nutrient: Nutrients that are needed in moderate supply for satisfactory growth. These are  calcium, magnesium and sulphur.



Layering: A method of propagation where you cause roots to grow along the stem of a plant while it’s still attached to the  mother plant.

Leaf Mold: this is the product created when fallen leaves have been shredded and/or composted.

Lime: aka Calcium carbonate is an alkaline compound used to raise the pH of soil.



 Macronutrient: This refers to a nutrient which is required in large quantities by a plant for normal growth. (NPK)

 Micronutrient: The nutrients that are needed in small amounts for a plant to grow normally. This includes iron, manganese, molybdenum, boron, zinc and copper.

 Mutation: Is a sudden change in the genetics of a plant, which leads to a new characteristic and that can be inherited.

Mycelium: A plural term for the network making up an underground fungus. When you dig in the soil and see the white stringy things in the soil, it means your soil is healthy. Those are very good and shouldn’t be destroyed.



Nitrogen: The element necessary for healthy leaf growth and greening. The signs of deficiency show up as yellowing of the older leaves.

 Neutral Soil: Soil with a pH between 6.5 -7.3 pH. This is neither acidic nor alkaline.

 Node: The location on the stem from which a new bud or leaf appears.



pH: The measure of the acidity or alkalinity of a substance. It refers to the relative concentration of hydrogen ions and hydroxyl ions in a solution.

 Permanent Wilting Point: The point of no return with soil dryness where a plant can no longer recover even if water is given.

Phloem: The nutrient conducting vessels found throughout the plant. Phloem tubes carry nutrients produced by the leaves down through the stems, branches, trunks and to the roots.

Phosphorus: The element necessary for seed and fruit growth and helps flowering and blooming. The signs of deficiency show by the plant being stunted and the stems and older leaves redden in color.

 Pleaching: The method of training a tree or trees to form an archway or dome.

Potassium: (potash) The element needed for strong root growth. As well as a plants’  hardiness, metabolism and disease resistance. The signs of deficiency show up as browning of the edges of the older leaves.



 Reversion: The term used to describe a variegated plant whose new growth is solid green, the plant is reverting back to all green.

 Rhizome: The growth of a horizontal underground stem that produces a new plant.

 Root Bound: Any plant or tree that has been in one container too long and its’ roots have grown tightly around and around inside.

 Rootstock: The lower portion of a grafted plant.

Runners: Long stems that grow from the base of the plant, and a new plant grows at the end of it, such as strawberries.



 Scion: The upper portion of a grafted plant.

 Shrub: A woody plant that branches near the ground.

Skeletonize: This refers to the damage cause by some pests, often worms. They eat all the green of a leaf and leave only the veins-or skeleton

Spike: A flower stalk with flowers attached directly to the stalk, no stems.

Spikelet: Refers to the single spike of flowers that rises out of an ornamental grass.

 Species: Genetically similar plants that grow true to type from a seed.

 Sterile: Plants or flowers that do not set seed.

 Stolon: Same as Rhizome but the stem grows horizontally above ground. See Runner.

Sucker: An enthusiastic shoot that rises from the main branches or roots of a tree. Summer pruning reduces suckering, dormant pruning increases it.



 Tap Root: The main root of a plant that heads straight down into the soil.

 Tender Plant: A plant that cannot handle any cold or freezing temperatures.

 Terminal Bud: Near the end of the growing season, the last growth bud produced on a shoot.

 Tree: A woody plant having six feet of clear stem before branching starts.

 Tuber: The fleshy, root part of a plant that is used for propagation.

 Tuberous: A plant grown from a tuber. eg. Tuberous Begonia.



 Vegetative Reproduction: Reproduction of plants using the methods of division, layering and cutting.

 Vein clearing: The lightening  or total loss of color in leaf veins. Usually the result of infection or deficiency in nutrients.



 Weed: Any plant growing in the wrong place.

 Worm Castings: This is soil that has passed through a worm’s digestive tract, which breaks it down into simpler forms that the plant can absorb easily.



Xylem: Nutrient and water conducting vessels found throughout a plant, they carry nutrients and water from the roots upward through the plant.


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