Protea: Greenhouse Plants
C – cool, minimum of 7°C (45°F) / W – warm, minimum of 13°C (55°F)
Mostly South Africa
Most of these bear spectacular flowers and were at their most popular at the turn of the 19th century. Their popularity has increased again recently but as cut flowers rather than cultivated plants. Beautiful and impressive displays of Proteas and other South African flowers have been staged at Chelsea Flower Show in recent years, which has no doubt brought them to the attention of plant lovers. A good variety of seed is available which should be sown as fresh as possible 6 mm (½ in) below the surface of a peaty seed. Germination seems to work best at about 18-21°C (65-70°F) but will be at best erratic, taking between one and three months. Prick the out as soon as they are large enough to handle. As a rule these plants dislike phosphates in the compost so a well-drained home-made peat and grit compost 3:1 in bulk is best. Either mix sources of nitrogen and potash into the compost or liquid feed regularly with a phosphate free fertiliser such as that produced by Chempak. Given careful watering, well-drained compost and light, cool airy greenhouse conditions plants should grow on and flower well.
Probably the easiest is Protea cynaroides which is the King Protea and has large pink flower heads. P. nana, the Mountain Rose, would be a good choice for a small greenhouse as it only reaches 60-90 cm (2-3 ft). Another species of modest size is P. scolymocephala which should flower in its second year although not profusely for another two or three years. However, as with all of these, the wait will be worthwhile as the flowers are unusual, attractive, long-lasting and can be dried and used for flower arranging.