Proteas are ancient plants, native to dry rocky slopes of southern Africa and Australia. The family Proteaceae is large and varied, comprised of over 1600 species. Their long-lasting, brightly colored flowers are commonly featured in high end flower shops. Most proteas are hardy to 20 degrees Fahrenheit. In colder climates they can be grown in pots and moved indoors over the winter. These unusual beauties can be grown with relative ease as long as their specific cultural requirements are met.
Select proteas that will grow well in your area. Consult your local nursery for a list of available species and specific care requirements.
Plant your proteas outdoors in early fall. Prepare a bed of extremely well-drained soil, in a spot that receives full sun. If your soil contains clay, amend it with gravel or sand so that it drains very quickly, because soggy soils are deadly to proteas. If your soil has less than perfect drainage, consider planting proteas in a raised bed.
Test your soil's pH with an inexpensive kit available from most hardware or garden stores. Acidify the soil, if necessary, with an amendment such as iron sulfate, elemental sulfur or aluminum sulfate as directed to achieve a pH between 3.5 and 6.5.
Plant your proteas, taking care not to disturb the fine surface roots. Make sure the soil surface of the potted plants is exactly level with the new soil. Leave ample space between plants and allow for plenty of air circulation to discourage fungal diseases.
Apply a 3-inch layer of well-aged, organic mulch to the soil surface, avoiding the plant stems. Do not use yard clippings or other green mulches because they may harbor fungi or other pathogens.
Water newly transplanted proteas carefully for the first one to two years, until they are established. Keep the surface roots evenly moist but avoid over-watering. Water established plants thoroughly every week or two during dry weather.
Avoid fertilizing proteas before they reach maturity. They are adapted to very poor soils, and can be harmed by even small amounts of phosphorous. Fertilize mature plants with very-low-phosphorous soluble plant food, diluted to half the recommended dose.