Gardening Definitions (G-I)

Genus
The category in botanical classification below family. A genus is a group closely related plants known as species. All the species of beech trees (for example), are grouped under the genus Fagus. Related genera are grouped in turn into a family, in this case Fagaceae. The common beech is identified by a genus and a species name, Fagus sylvatica. A natural variety is identified by a third name, such as Fagus sylvatica var. heterophylla, and a cultivated variety (or cultivar) by quotation marks, as Fagus sylvatica 'Dawyck'. A cross (or hybrid) between two species is identified by a multiplication sign: for example, the hybrid willow Salix x rubens
Germination
The initial stage of a plant's development from a seed. Germination periods vary: given the right conditions of temperature, moisture, light and oxygen, it may occur within days or take weeks or months.
Glabrous
Smooth or bare - used to describe a part of a plant that is hairless.

Glaucous
Describing the grey-blue colour of some plants, or the grey or white waxy bloom on them. An example is the white bloom on the leaves of some brasicas, particularly cabbages, and succulents such as sedums.

Grafting
Propogation plants by joining a stem or bud of one plant to the root of another so they unite to form a new individual. It is widely used in cultivating fruit trees and roses.

Habit
The characteristic shape and growth form of a plant.

Half Hardy
Frost tender species of plants that can only be grown in the open reliably during summer - for example, canna and French and African marigolds.

Half Standard
A tree or shrub, usually with a single stem growing 75cm-1.2m high before the head branches.

Hardening Off
The gradual acclimatisation of tender and half hardy plants, grown under heated glass or other forms of protection, to outside conditions. Plants are usually placed in a coldframe in late spring, with air gradually admitted until the lights of the frame are left off entirely.

Hardy
Plants which survive frosts in the open, year by year.

Herbaceous
Any plant that does not form a persistent woody stem. Botanically, the terms applies to annuals, biennials and perennials - but by common usage is chiefly associated with perennials which die down in autumn and reappear the following spring.

Hose in Hose
An abnormal floral mutation in which flowers appear to grow in pairs, one arising from the centre of another. Primrose and polyanthus are examples.

Humus
The dark brown residue from the final breakdown of dead vegetable matter. The term is often used to describe partly decayed matter that is brown and crumbly, such as well made compost or leaf mould.

Hybrid
The result of crossing two distinct varities or, occasionally, genera. Hybrids may either show a blending of characteristics from each parent or favour one more than the other.

Incised
The margins of the leaf, stipule or bract that is deeply and sharply toothed or lobed.

Inflorescence
The arrangement of flowers on a stem, often referred to as a flowerhead.

Inorganic
A chemical compound or fertiliser that does not contain carbon. The term is applied to synthetically produced fertilisers, although some naturally occurring plant nutrients have inorganic origins, as, for example, the mineral fertiliser rock phosphate.

Technical Stuff - Abbreviations

We try to avoid as many technical terms wherever possible, but sometimes they are unavoildable and manage to slip into the posts - the definitions below will help make them clear.

Alpine
Any plant that is native to montainous regions (as a general rule), growing between the tree line and permanent snow line. 'Alpine' is also loosely applied to any small plant suitable for growing in a rock garden.

Alpine House
A greenhouse that has continuous ventilation along the eaves, vents at a bench level and, ideally, a door at each end. Not heat is necessary; however, as alpine plants dislike cold wet conditions, some growers maintain their alpine houses at 1ºC (34ºF).

Annual
We al have these in our garden! A plant that completes its life cycle in a sungle growing season - from seed to floweing, to setting seed and dying.

Basal Leaves
Leaves arising directly from the crown of a plant or a very short stem.

Biennal
A plant which takes two seasons to complete its life cycle - i.e., the foxglove. In its first year it forms leaves; in its second year ir forms flowers and seeds, then dies.

Bract
A modified leaf which is sometimes brightly coloured and conspicuous to attract pollinating insects, such as the scarlett bracts of poinsettia.

Bulb Frame
A coldframe in which bulbs in pots can be plunged in sand, soil or gravel for winter to protect them from frost. A blub frame can be used instead of an alpine house.

Capsule
The dry or nearly dry fruit containing loose seeds. When the capsule is ripe the seeds may be shaken out by the action of the wind or passing animals, or it may split, forcibly rejecting the seeds.

Chitting
Sprouting tubers, particularly potatoes and dahlias, before planting. Also applied to seeds germinated before sowing.

Chlorosis
The loss or insufficiency of chlorophyll - the green pigment in the cells of leaves and young stems. The lack of chlorophyll causes the leaves to appear bleached or yellowish. Chlorosis is usually due to mineral deficiency, but viruses may be a cause.

Cloche
Sheets of clear glass, rigid or plastic film that are used for raising early crops in open ground, and for protecting plants from bad weather - alpines, for example.

Clone
A group of identicial plants raised from a single parent plant by cuttings or division rather than by seed.

Compost
A mixture of loam, sand, peat, leaf-mould or other materials used for growing plants in containers. The term also refers to organic material obtained by stacking plant remains such as vegetable trimmings, straw and grass mowings until they decompose.

Compound
Leaves, flowers or fruits having two or more similar units.

Conifer
Tree or shrub, usually evergreen and having linear or needle-like leaves, and which usually bears its seeds in cones.

Corm
The underground storage organ of some plants, including crocuses and gladioli. Similar to a bulb, it consists of a swollen stem at the top which produces shoots and a new corm.

Corona
The trumpet or cup like flower part of such genera as Narcissus and Hymenocallis.

Cotyledon
The first leaf or pair of leaves to appear when a seed germinates. They are also called seed leaves because they are formed within the seed. In some cases, such as the broad bean, the seed leaves remain underground - the first shoot to appear bears the true leaves. Seed leaves frequently differ in shape from true or adult leaves.

Crown
The part of an herbaceous perennial at soil level from which roots and shoots grow.

Cultivar
Cultivated variety; a variant of a plant produced in cultivation as opposed to one that occurs in the wild.

D-F coming next week - anything you would like to add to our garden abbreviations?