Forcing

The acceleration of growth by gradually increasing temperature, water supply, and quickly available plant food such as sodium nitrate.

Frame

See Cold frame or Hot-bed.

Fresh-burned Lime

See calcium oxide.

Friable

Easily crumbled, mellow, allowing free and unobstructed root development. A term used in describing a condition of soil.

Frozen Ball

A solidly frozen ball of earth containing a major part of the root system of a plant (usually a tree) which is being transplanted. Ball of earth must be frozen sufficiently solid so that it will not split during normal transplanting operations.

Fungus

A flowerless plant not containing chlorophyll and generally parasitic upon another living plant.

Furrow

A shallow trench made by or as by a plow.

Gall

An abnormal swelling or excrescence caused by gall flies.

Gas Lime

Is a mixture of slaked lime or calcium hydrate, and carbonate of lime, together with sulphites and sulphides of lime. These last are injurious to young plant life until they have been exposed to the air for some time. Gas lime usually contains 40 per cent, of calcium oxide and sometimes a small percentage of nitrogen.

Girdle

n. An incision or several incisions which sever the cambium layer of a woody plant to the woody tissue and for the whole circumference of the stem. It may be a circular cut, a spiral cut, or may consist of several cuts more or less widely separated, but whose horizontal projection would form a closed circle. v. To kill a tree by girdling it.

Ground Cover

Small plants or vines, usually growing not more than a foot high, which will spread out and conceal the surface of the ground from view.

Grubbing

Clipping and digging out roots, stumps, etc. Turning over and breaking up the sod with a grub hoe or mattock.

Guying Trees

Placing wires or stays on trees or portions of trees to prevent them being blown over or broken by the wind; more especially the placing of three or more guys on trees recently transplanted to hold them firmly in place until an adequate root system has been established, and to prevent swaying of the trees and loosening of root system.

Hammock Land

Land, mostly in the southern part of Florida, covered with luxuriant growth of trees (hardwoods, or cabbage palms and palmettos). The soil is rich in fertilizer value.

Harden-off

To so care for plants previously grown in a greenhouse that they will be able to withstand normal outdoor exposures. It is customary to move such plants from the greenhouse to cold frames.

Heave-out

The partial lifting of plants out of the soil by frost action. This is apt to occur when ground previously deeply frozen and thawed out on top is again frozen. The layer of frozen soil beneath, which has not yet thawed out, forms an unyielding barrier and the expansion of the soil in freezing is then wholly upward. The stresses thus caused are enormous and plants are lifted sometimes almost wholly out of the ground.