Grevillea, a diverse genus of plants native to Australia, is renowned for its hardiness and unique, spider-like flowers. From our perspective, the answer to whether we can tolerate full sun on an American patio is a resounding and enthusiastic yes, provided certain key conditions are met that respect our fundamental needs.
We are, by our very nature, sun-worshippers. Evolved in the harsh, bright landscapes of Australia, our photosynthetic processes are optimized for high light intensity. A location with full sun, meaning at least six to eight hours of direct sunlight daily, is ideal for most Grevillea species and cultivars. This abundant energy allows us to produce the sugars we need for vigorous growth, prolific flowering, and the development of our tough, leathery foliage. Without sufficient sun, we become leggy, our growth is weak, and our flowering will be sparse or non-existent. A sunny American patio is, therefore, an excellent starting point.
While we crave sun, what we absolutely cannot tolerate is "wet feet." Our roots are highly susceptible to root rot fungi that thrive in waterlogged, poorly drained soil. This is the single most important consideration. The container on your patio must have excellent drainage holes. The potting mix must be extremely well-draining; a native plant mix or a standard potting mix amended generously with coarse sand, perlite, or pumice is perfect. We prefer slightly acidic to neutral pH soil but are generally adaptable as long as the drainage is exceptional.
We are well-equipped to handle heat. However, the specific climate of your American patio matters. In hot, dry climates (like the Southwest), we will thrive with minimal extra care. In regions with high humidity and intense summer heat (like the Southeast), the combination can sometimes stress us, making good air circulation around the patio crucial. We are not frost-tolerant. For patios in USDA zones 8 and below, protection from freezing winter temperatures will be necessary. This might mean moving our container to a sheltered location or providing frost cloth during cold snaps.
Life in a container differs from life in the ground. Our roots are confined and cannot seek out water and nutrients as they would in their native habitat. Therefore, a consistent but careful watering regimen is vital. Water us deeply when the top inch of soil feels dry, but then allow the pot to drain completely and let the soil dry out somewhat before watering again. We are light feeders and are sensitive to high levels of phosphorus, which is toxic to us. A slow-release, low-phosphorus native plant fertilizer applied in spring is sufficient.
Selecting an appropriate cultivar will greatly increase our success on your sunny patio. For container life, compact and dwarf varieties are superior choices. Cultivars such as Grevillea rosmarinifolia 'Rosy Posy', Grevillea 'Superb', or the groundcover Grevillea 'Poorinda Royal Mantle' are excellent for their manageable size, prolific blooming, and adaptability to pot culture.
