Phymaspermum acerosum can be propagated by sowing seed in spring or autumn, or by cuttings. Once the flowering season has passed and the new shoots begin to grow, heel cutting or stem cuttings can be taken. Select healthy cutting material. Use a rooting hormone, and place cuttings in trays with a light, well-drained medium, under mist with bottom heating. Under these conditions, cuttings should root within weeks.

Once the cuttings have rooted, remove them from the bottom heating and harden them off under a shade net for a week. Pot the cuttings up and leave them under the shade net for three weeks. Thereafter, move them into a sunny area.

Phymaspermum acerosum planted en masse with Leonotus leonurus and different types of sagebushes such as Hemizygia or Syncolostemon, which flower at the same time of year, can brighten up any dull garden by adding contrasting colours as well as give it body and form. It can be used in mixed borders as one of the larger shrubs, planted in the centre or the back of the bed. Geelblombos prefers a sunny area in the garden where the soil is well-drained and well composted. Once it has finished flowering, prune the bush back to promote bushy growth.