Restio similis is best propagated by seed. Sow the seed in early winter (May–June) when the temperatures drop to 5–10ºC at night and 15–20ºC in the day. Treat the seed with smoke derived from burning dry and wet fynbos plant material to break seed dormancy and stimulate the germination. Treatment can be done in a smoking tent or use the smoke packets. Soak the seed or dust them with fungicide, and water the sowed seeds with fungicide once a week to prevent fungal infection.

Lay the seed on the well-drained fynbos soil and cover with a fine-sieved fynbos soil mixture. The seeds are very small, handle them gently when laying them on the prepared soil. Use a fine rose watering can or fine hose nozzle when watering. The seed takes about 4 weeks to germinate. Feed the seedlings with organic fertilizer during the growing season to prevent yellowish and unhealthy plants. Keep your seedlings moist, not dry or too wet.

When the seeds have germinated, the first leaf-like, green cotyledon lifts the seed coat above the ground. The seedlings grow very fast and will need to be potted to reduce the food competition and prevent them from becoming yellowish. The seedlings become ready to plant in the open ground after a period of 2 years. They are plants that resist garden pests. Plant your restios in the garden during a normal growing season at the beginning of the rainy season; this applies for winter and summer rainfall areas. Plants prefer full sun in a well-drained, acidic soil and plenty of air movement. Mulch the bed to reduce water evaporation, keep the roots cool and prevent weed growth. Once the plants are established, they will need less water and they will grow to fill up the area.