Sow the seed in autumn, using a medium that is light and has good drainage. A mixture consisting of equal parts of sand and compost or plain, coarse river sand can be used. Cover the seed with a thin layer of bark, sand or the medium and then water. Keep the seed tray in a covered area that provides enough good light and ventilation. Never allow the medium to dry out completely, or to be overwatered. The appearance of the first 4 true leaves, after 4–9 weeks, indicates the readiness of the seedlings for pricking out. Like all buchus, the fine roots must be handled with care.

The potted plants are now placed in a shady area for 3–4 weeks to harden them off, before placing in the sun. This will also be a good time to pinch out the growing tips of the seedlings, as this promotes a more bushy growth habit. Some nurseries also plant small buchu seedlings or plantlets grown from cuttings, in plugs after rooting. By using the plugs, the mortality rate is being decreased, plants grow quicker and plants get to be pruned between 2–3 times before being transplanted into larger bags. Regularly feed the young seedlings with some balanced nutrient products. Plants will be ready for transplanting into the garden after 8 to 9 months.

The taking of heel, tip or semi-hardwood cuttings is another way of propagation and will be the quickest way of achieving a flowering plant. Prepare cuttings of between 25–55 mm, remove about a third of the foliage and cut them below the node. Dip the cuttings in a rooting hormone and place in trays with a medium consisting of equal parts of bark and polystyrene. The cuttings are now placed in a mist-unit with heated benches. It takes 9–11 weeks for roots to develop. The rooted cuttings can then be moved to hardening-off for 2–3 weeks.

Pot the rooted cuttings in a well-drained soil mix and place in a shady area for 2–4 weeks to harden off. After this, they can be moved into full sun.

Diosma haelkraalensis will thrive in full sun, in well-drained and stony or rocky soil, where it is planted amongst other fynbos species. The ideal time for planting is between autumn and winter, which is the rainy season in the fynbos. This will enable plants to have a better chance of becoming established in the garden, before having to cope with the drought and extreme heat of summer.

Plant this buchu with: Acmadenia heterophylla and A. mundiana, Agathosma apiculata, A. collina, A. gonaquensis and A. serpyllacea, Coleonema album and C. pulchellum, Cotyledon orbiculata, Euchaetis meridionalis, Helichrysum dasyanthum, Restio dispar, Lampranthus aureus, Leucospermum patersonii, Lobelia valida, Pelargonium betulinum, Protea compacta and P. obtusifolia.

Planting at intervals of 20 to 30 cm, should provide enough space to encourage growth. This relatively dense planting is preferred by buchus, as it helps to retain soil moisture. Provide a good, thorough watering in winter. In summer, watering should just be moderate; however, do not allow plants to dry out completely. Regular mulching also aids in keeping the roots and soil cool in summer.