Although Protea aristata is slow-growing, this compact and neat shrub will be one of the longest lived proteas in the garden, reaching a possible age of 50 years. Many other proteas tend to become scraggly, taking on an untidy appearance in their old age between 8 and 10 years, but P. aristata retains a very neat shape throughout its long life. To ensure this neat growth, one should take care to regularly prune off all faded flowerheads. P. aristata will thrive in well-drained soil, in a full sun position in the garden provided there are no other encroaching shrubs or plants, so make sure it has plenty of space around it. It performs best in well drained acidic sandstone soils, although it can easily adapt to granitic media providing it is well draining. In the garden it is an excellent specimen for the mixed Fynbos garden, or can be planted in rock garden pockets. Once established, P. aristata proves to be very waterwise. It can be grown in ground in frost-prone areas and handles temperatures as low as -4°C, is frost tolerant and can also be grown well as a container specimen. It will not grow well in wet sites and is even grown at Kirstenbosch National Botanical Garden with some difficulty.

Protea aristata is best propagated from seed. The best time to sow protea seeds is late summer to autumn (March to May in the southern hemisphere) and only plump, fresh seed should be selected for sowing. Many species of Protea have the adaptation of serotiny to survive periodic fynbos fires. Seeds therefore germinate much more successfully after being smoke-treated. Protea seeds are sensitive to excessive amounts of water and are susceptible to rotting, thus it is essential to sow them in a conventional seed tray in a well-aerated, well-drained medium consisting of coarse river sand mixed with finely milled bark (equal ratio). Seeds can be slightly covered with the medium, but make sure not to cover them too much as this will affect germination. If using the tent method of smoke treatment, allow trays to stand in the smoke for two hours and then water the trays to rinse the smoke deposit into the medium. Place treated trays under cover in a shade-house where they will receive optimal fluctuating temperatures of warmer days and cooler nights, between 10°C and 20°C. Prick seedlings out once the first true set of leaves emerge. Plant these into individual pots or containers into the same coarse medium. Water seedlings thoroughly and place under light shade for 7 days to harden off before placing in full sun. Transplant growing plants as required, preventing any unhealthy root formation (Brown et al. 2013).

When cultivated in the artificial garden environment, many species of Protea are susceptible to diseases and pests. Caterpillars, nematodes, scale insects, tipwilters and snout beetles are all possible pests of Protea aristata (Brown et al. 2013). A variety of fungi can cause death of plants. Phytophthora cinnamomi causes root rot and is the most threatening root disease of proteas since it causes heavy losses during warmer summer months.

For more detailed information, refer to Grow proteas in the Kirstenbosch Gardening Series where pests and diseases, as well as their remedies, are discussed in depth.

Acknowledgements: Thanks to Alice Notten who assisted with the writing of this article.