There are two commonly used propagation methods for this plant: sowing seeds and dividing rhizomes. Make sure you do not disturb the roots too much. Restio roots, like any other fynbos plant, are very sensitive. You need to be careful that they are not damaged. Divide rhizomes early in winter before the new culms arise from the rhizomes. Keep the plants in light shade and water them very well. Feed the plant every second week with organic fertilizer to encourage fast growth and the production of new culms.

The ideal time to sow seeds is in autumn (April-May) when day and night temperatures fluctuate between 22 and 10 degrees Celsius. Soak seeds for 24 hours prior to sowing. Use a mixture of milled bark and sand (fynbos mixture). Sow seeds in trays with the fynbos mixture and cover them lightly with sand. Sand, instead of milled bark, is preferred for covering seeds, as they are very tiny.

Seeds can be treated with smoke to stimulate germination. At Kirstenbosch National Botanical Gardens fynbos material is burnt in an enclosed container and the smoke is channelled into a tent filled with seedling trays. Use a tent to lay seedling trays out and then allow smoke to settle in. After an hour, move the trays out and house them in a well-ventilated area. Elegia aggregata germinates after 4 to 6 weeks. The smoke from the fynbos material produces a chemical cue that breaks the dormancy of seeds. Alternatively, treat seeds prior to sowing by using instant smoke primer.

Trays must be kept moist, but not wet, as that can cause seeds and seedlings to rot (damping-off). This is a common disease in restio seedlings. Prevent this by spraying with fungicides every two weeks after seedlings have emerged. Generally, restios are disease resistant once they pass the seedling stage. They only need sufficient water.

After germination, seedlings must be planted into plug trays to allow them to form a root ball so that they can grow stronger. Feed them with organic fertilizer to encourage growth. After 6 months, individual seedlings must be transplanted into 1 kg bags, again using the fynbos mixture.

The best time to plant Elegia aggregata in your garden is at the beginning of the rainy season. Dig holes and plant them at the same level as they were in the bags. Use two spades of compost during the planting process and mix with soil. Mulch, as this is beneficial to all fynbos plants by preventing evaporation and keeping plants moist.

Elegia aggregata grows well provided soils are well-drained. The other main requirements for successfully growing this plant are full sun and plenty of air movement and regular watering.

Elegia aggregata is tufted and can make a good contrast against a planting with small leaved ericas e.g. Erica verticillata and Erica sessiliflora. Leucadendron spissifolium and Phylica pubescens are good subject to be planted with this plant.