PlantFiles: Limestone Sugarbush
Protea obtusifolia

This is an easy garden protea. It can even withstand more alkaline soils up to a pH of 8.4 though it prefers a more acidic soil. It also does well growing on the coast and once established can take temps down to 30 degrees without getting frost damage. However, protect young plants from any frost.
Good for a hedge but prune when young to get a dense structure.

The flower stalks are shorter than many of the other showy proteas so this one is not used in the florist trade.

In general:
The genus Protea was named after the Greek God Proteus who could assume many shapes because like him, Proteas come in so many different forms. The king protea, Protea cynaroides is the national flower of South Africa where most originate from the mountainous coastal land of Cape Flora region. They are now grown in New Zealand, Australia, California and Hawaii.

Proteas will attract bees and birds to your garden. They are full of nectar and often are called sugarbushes. Some are so sticky from nectar, insects actually get trapped in them. They grow best in full sun where the days are warm and the nights cool. Generally protea like acidic, well draining soil. You can add peat moss and bark to a good soil mix or use a soil less mixture. Add perlite or pumice to increase drainage which is most important to have. Water moderately until well established then they are somewhat drought tolerant, needing only occasional deep watering. Most can tolerate temps down to 25 if established though prefer no frost.

Protea are not heavy feeders. According to the protea expert, Dennis Perry, they need much less fertilizer, about 1/8th to 1/4th of other plants. Proteas like to have sulfur, magnesium and iron available to them in higher amounts than you would ordinarily use on other plants. However, phosphorus and calcium is harmful to them, so select fertilizers that are very low in these 2 nutrients. Mr. Perry suggests using Epsom Salts and Iron sulfate as soil amendments. A slow release, low phosphate fertilizer in late winter and mid summer is best. You do not want to encourage rapid growth as this may weaken the plant.

Unfortunately, seedlings from species can be difficult to keep alive due to fungal diseases. Vegetative propagation may be easier. To propagate hybrids you need to take cuttings of semi hardwood in late summer and autumn. Many root easily.

Prune after your protea flowers, removing old blooms and shaping plant. Do not prune stems that have not bloomed for these are next years blooming wood.