As a garden shrub, Diastella thymelaeoides subsp. meridiana adds a continuous structural element to smaller gardens, and its long flowering period adds colour and beauty to a mixed fynbos border or rockery. Place it alongside Leucospermum bolusii, Serruria adscendens, Elegia stipularis, Erica gysbertii or E. pluckenetii. Plant D. thymelaeoides subsp. meridiana in a sunny area in well-drained acidic soils or a mix of 1 part coarse grit and 1 part compost. Diastella prefers good air circulation and will not tolerate high humidity. Plant it in the garden in early autumn when it is cool, and water well. Once established, they will tolerate less frequent watering. Plants can be pruned lightly after flowering to maintain a neat compact growth form and to encourage flower production.

Diastella thymelaeoides subsp. meridiana can be propagated by seed or cuttings. Seed collection is often difficult and time consuming, and seeds are hard to find as they are removed by ants or rodents from the flowers. Flower heads can be bagged, and when they begin to disintegrate, the fruits can be collected. Only mature, plump seeds should be collected for sowing. Sow seeds in early summer or autumn when fluctuating temperatures of 4–10°ᶜ  at night and 20–28°ᶜ during the day are ideal. Germination is further improved by smoke treatment which can be applied either by soaking the seeds in aqueous smoke treatment or by placing the sown seed trays inside a tent, filling it with fynbos smoke, and leaving it for 2–2.5 hours or until the smoke settles. Sow seeds either in the open ground or into trays filled with a well-drained mixture: 8 parts finely milled pine bark and 3 parts coarse sand. The ideal PH for growing diastella is 4.5–5.5. Sow seeds at a depth of 1.5 times the size of the seed, cover with dry sand, water well, and place in a sunny position with good air circulation. Seeds can be dusted with a systemic fungicide containing metalaxyl to prevent pre- and post-emergence damping-off fungi. After germination, when seedlings have some true leaves, they can be pricked out into pots.

When propagating from cuttings, collect tip or heel cuttings 30–70 mm long, from the current season’s growth, in spring or autumn. Firm shoots that have completed their growth spurt, are ideal. Remove the leaves from the lower third of the cutting and treat them with a rooting hormone suitable for semi-hardwood material. Place in plug trays filled with an airy and well-drained medium of 1 part bark and 1 part polystyrene balls. They root well if placed in a greenhouse with hot beds and an intermittent misting system; however, they must not become too wet. Use a general fungicide to control fungi that may affect cuttings. Rooted cuttings are planted into pots and hardened off under 50% shade for three to four weeks before being placed in full sun.