To grow any restios successfully, provide a position in the garden with full sun, well-drained soil and plenty of air movement. The plants adapt to a wide variety of soil types but do not like to grow in heavy clay soils.

Restios are adapted to a winter-rainfall climate, thus, their normal growing season is from autumn (April to August in the southern hemisphere) to early summer (October to December). The best time to plant restios in both summer- and winter-rainfall areas is in autumn (April and May), which is at the beginning of the rainy season of their winter-rainfall habitat. Elegia fenestrata prefers a marshy situation and should be watered regularly if planted in a year-round dry situation. 

The life-cycle of Elegia fenestrata stretches over 3 years. During the first year, a crop of new culms is formed; during the second year these stems flower and produce seeds; during the third year the stems stay green and produce food for the new growth and in the fourth year the stems turn brown and die. The old culms are retained and if not removed make for an untidy looking plant, as they tend to fall over. If the dead stems have to be removed, only the outer layer of dead stems should be cut off. It is important not to damage the new growth, as once damaged, the stems will die. The plants cultivated at Kirstenbosch National Botanical Garden last for about 4 years in the Garden, and then have to be replaced by new seedlings.

Most restios will respond to regular watering by showing more robust growth, but they are essentially plants that are adapted to a long dry season. Like most other fynbos plants, restios will benefit from a mulch of well-rotted compost. The mulch keeps the roots cool, reduces water evaporation and reduces the germination of weeds. 

Restios, in common with most other fynbos species, do not like to have their roots disturbed. They are, however, much more robust growers than most fynbos plants and do not seem to be plagued by soil-born fungi or many other diseases.

Restios respond well to regular feeding with low concentrations of nutrients, so, feed with liquid organic fertilizers. The potting soil can be mixed with a small amount of ammonium sulphate or a slow-release fertilizer with a low phosphate content. 

These plants are best grown from seed. The only other method is by division of the entire plant, which is not recommended, as the root system of E. fenestrata is very sensitive and division is rarely successful.

The ideal time to sow seeds is in autumn (April–May) when day and night temperatures fluctuate between 10º and 22ºC. 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. The seeds react well to treatment with smoke or with the ‘Instant Smoke Plus’ seed primer. The smoke from burning fynbos material produces a chemical cue that breaks the dormancy of seeds. Without this treatment the germination rate is poor. Germination should take about 4 to 6 weeks .

Seed trays must be kept moist, but not wet, as that can cause seeds and seedlings to rot (damping-off). Prevent this by spraying with fungicides every 2 weeks after seedlings have emerged. This is a common disease in restio seedlings. If the seedlings show signs of damping-off, the affected ones should be gently removed and the remainder treated with a fungicide. Generally, restios are disease resistant once they pass the seedling stage. 

The seedlings can be transplanted when they have formed one or more real culms. They are generally very hardy at this first stage and adapt easily to the new growth medium. The soil mix should be fairly light and very well drained with a pH slightly below 7. Place the seedlings in the soil so that the roots are just below the surface of the soil (the root shoulder should not be exposed); use 12 packs, 9 cm pots or multitrays, as long as there is not an overwhelming amount of soil for the young roots to cope with. When the plants are ready for their next transplant, they will need to be potted on into larger bags or containers to grow on; look for roots appearing out the bottom of the containers to know when they are ready. A slow release fertilizer can be mixed into the soil before transplanting. 

The young plants are ready to plant in the open ground after a period of about 2 years when they have formed a good root ball in their pots /plant bags.