1. Well-draining soil is a must. The soil should be fairly inorganic in nature such as sand or decomposed granite. They like acid soils but can tolerate a wide range. There are very easy ways to acidify soil, but it is not very common for our San Diego native soil to have a pH that will be too unfavorable for these plants.
2. Plant in full sun. It is important to give them at least 5-6 hours of sun if you want good flower production and a normal growth habit. We are east of San Diego where the hot sun can be brutal, but they can handle it. We do lose flowers when temps go above 100. The plants themselves rarely suffer from the heat.
3. No root disturbance. When transferring from the pot to the ground or into another pot, be careful not to disturb the roots. It doesn’t take much disturbance to kill the plant. When planted in the ground, we recommend not excavating around the plant for about a 3’ diameter circle with the plant in the center. We are very careful about pulling weeds with large tap roots. This also means you cannot transplant the plant if you don’t like where you put it.
4. Water is crucial. While they naturally grow in arid locations, it is best to keep the soil consistently moist the first year and continue to water regularly for good flower production. If growing in a pot, watch for drying out. When the top inch is dry, time to water.
5. Say No to fertilizer! Proteas are very effective at extracting nutrients from poor soil. Generally, fertilizing is not necessary for plants planted in the ground and phosphorus is especially not tolerated. Protea grow in soil that is very low in phosphorus and these plants have not developed a mechanism to stop intake of phosphorus. They take in too much if it’s readily available and can easily overdo it. Planting protea family plants in old vegetable or rose gardens is not recommended.