Oleander-leaf protea - 5 seeds
Oleander-leaf protea - 5 seeds
This is a large ornamental shrub with a fairly long flowering time, producing large flowers, varying in colour from creamy-green through silvery pink to deep carmine. A 'beard' of purple-black to pure white hairs sets off the colour of the inner bracts.
In cultivation Protea neriifolia has a wider tolerance than most other proteas and can be grown in a climate with wet winters and dry summers, as well as in a climate with dry cold winters and wet summers, even withstanding light, but brief frosts. The shrubs are quite fast growing and can reach a height of 1,5 m in about five years from seed, eventually reaching a height of 3 to 5 metres and living for 15 years or more. Seed grown plants are generally about four or five years old before they flower and the plants tolerate, even benefit from having their flowers cut off every year. Older plants can get woody and unattractive, with quite short side shoots, so to keep a plant in shape and to encourage the development of new shoots and long stems, the stems bearing old flower heads should be cut back.
Protea neriifolia can be propagated from seed or from cuttings. Good colour forms or cultivars have to be propagated from cuttings. Cuttings are made from semi-hardwood, 6-10 cm long, of the current season's growth, in autumn or spring. The cuttings are dipped for about four seconds in a rooting hormone solution and placed in a growing house with bottom heat (25ºC) and intermittent mist. The rooted cuttings are potted up when the roots are well developed and planted out in the late autumn in South Africa, or in spring in colder areas. The large furry nut-like seeds have to be treated during storage or prior to sowing with a systemic fungicide like Apron, (active ingredient metalaxyl) and sown from the middle of March, when the day temperature starts to drop. The seed is sown in open seedbeds, in a light, well drained soil and covered with a layer of sand (about 1 cm or 1½ times the size of the seed). The bed is then covered with a grid against the attacks from birds and rodents. The seed will germinate three to four weeks after sowing.
Protea neriifolia has quite hard, leathery leaves, which protect it against most insect attacks and not much damage to the leaves is visible, except from leaf borers. Like all other proteas, the most harmful and destructive diseases are fungal. Most losses occur during the summer months when a virulent root fungus, Phytophthora, can attack the plants. Control through the use of fungicides in the garden is difficult and expensive. By the time the plant shows distress, it is normally too late to arrest the problem. The best methods of control are cultural, i.e. water the plants early in the morning; keep the soil surface cool by mulching; remove diseased plants immediately; do not overwater in summer and prune and remove diseased material.
Protea neriifolia occurs in fire prone vegetation, where natural fires occur every ten to thirty years. This 'Mediterranean' type of vegetation grows in soils with very low amounts of nutrients. These nutrients are used up by the plants during their lifetime and need to be returned to the soil to provide the food for a new generation of plants. Protea neriifolia is adapted to survive the fires by keeping its seeds safely in the old seedheads, which will only be stimulated to open and release the seeds when the plant dies or is killed by fire. These natural fires occur mainly in late summer or autumn and are followed by the first winter rains, which provide the moisture the young seedlings need to grow to a size at which they can survive the long, hot summer.