Protea magnifica is a spectacular garden shrub in many situations. It requires good drainage and will not do well in damp, humid gardens. It prefers to be planted in full sun and must have good air circulation.

It is an easy plant to grow in well-drained acid soils and can tolerate frost up to about -8°C and can withstand some wind, but may show signs of foliage burn from excessive salt winds. They do not grow well along coastal ranges that are covered with moist fog through the year. Do not disturb their roots as protea roots are very susceptible to infection if they are tampered with. Proteas are light feeders that have adapted to very nutrient-poor soils and will die if strong fertilizers and manure are used.

Protea magnifica can be propagated from seed or from cuttings. Seed germination is somewhat unpredictable, starting as early as 21 days after sowing and continuing for up to two months. Sow the seeds in autumn (mid-March) into well-drained soil and lightly cover with sand or fine-milled bark and keep moist. Once the seeds start to develop their first true leaves, transplant them into individual containers. Seedling growth after germination is slow as most of them take up to six years to reach flowering stage.

Cuttings can be taken from semi hard wood in late spring or autumn. Collect cuttings from disease-free plants that are not yet flowering. Leaves on the basal third of the cutting should be stripped off and ensure that the cutting is cut just above a potentially sprouting bud. Dip the cutting in a rooting hormone and place into a well-drained medium under intermitted mist with a bottom heat of 25°C. Cuttings will ensure that the desired characteristics are maintained, whereas plants sown from seed might show variation from the parent plant particularly in flower colour.

The plant is not noticeably affected by insect pests but can be seriously affected by fungal diseases of the leaves. This normally happens when the plant is grown in humid or shaded localities. The fungal disease manifests themselves as deep reddish-maroon blotches on the leaves, which is followed by defoliation. A good way to prevent this from happening is to spray the plant regularly from seedling stage to maturity with a copper-oxychloride based fungicide. However seriously diseased, adult plants rarely respond to treatment and should rather be removed and destroyed.