This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Popularly known as "Genista" in the trade, this charming Leguminous plant from the Canary Islands has for many years been cultivated in thousands by market growers as a winter-flowering shrub. Plants are raised from cuttings of the half-ripened shoots inserted in very sandy soil in March and April, about three dozen being placed in a well-drained 5-in. or 6-in. pot. If kept close and warm they root in five or six weeks, and may then be moved singly into small pots. As these become filled with roots, the young plants are transferred to 4-in. or 5-in. pots and grown on steadily in genial warmth and moisture. The tips of the shoots are pinched out from time to time to make the plants bushy. During the summer months more air is given to harden the plants, and they are grown steadily throughout the autumn and winter months in a greenhouse temperature. In March following they will be large enough to move into 5-in. and 6-in. pots, using a compost of good yellow loam with a dash of silver sand and leaf mould, or well-rotted manure, and potting firmly. During active growth the plants are syringed daily, this being necessary not only to promote growth but also to check attacks of Red Spider. By the following winter, plants thus grown become fine bushy specimens, each shoot being laden with a truss of bright golden-yellow flowers. Plants in 5-in. pots realize from 6s. to 12s. per dozen, higher prices being obtained for particularly fine specimens in larger pots. The variety superbus is superior to the ordinary form, and is remarkable for its fragrance.