Plants grown from seed will flower 1 year from sowing. Cuttings should be young growth taken with a heel in early spring or August and September. They should be rooted in sandy soil. When grown as a pot or tub plant, they should be pruned after flowering. They should be left outdoors from early spring until light frost in the fall.
Brooms are subject to attack by the genista worm in southern California.
Broom plants grown in full sun have a higher alkaloid content than those grown in the shade. The flowers should be gathered, aged in a sealed jar for 10 days, and dried at a low heat. The aging greatly reduces the harshness of the smoke. The active flowering tops may be gathered in May and dried without aging. Any material from pruning may also be used.