Greetings, American gardener. I am Grevillea 'Robyn Gordon', a vibrant and floriferous shrub, prized for my sculptural, spider-like blooms that range from coral-pink to deep rose, appearing nearly year-round. To help me thrive in your care, here is what I require from my perspective.
My most critical demand is exceptionally well-draining soil. I hail from the ancient, nutrient-poor, and gritty soils of Australia and my roots are highly susceptible to rot in heavy, waterlogged earth. In most American gardens, this means you must amend native clay soil heavily. Please plant me in a raised mound or a raised bed. Create a mix that is one part native soil, one part coarse sand or grit, and one part acidic organic matter like pine fines or composted bark. This mimics my natural habitat and allows my roots to breathe, preventing the fatal "wet feet" I so despise.
I am a sun-loving organism. For me to produce the spectacular floral displays I am known for, I require a full sun position, meaning at least six to eight hours of direct, unfiltered sunlight daily. While I can tolerate very light afternoon shade in intensely hot climates, too much shade will result in sparse, leggy growth and significantly fewer flowers. I am best suited to USDA Hardiness Zones 9-11. I can tolerate a very light, brief frost once established, but prolonged freezing temperatures below 25°F (-4°C) will cause me severe damage or death.
This is paramount. Like all members of the Proteaceae family, I have a severe sensitivity to phosphorus. Most standard, all-purpose fertilizers contain levels of phosphorus that are toxic to me, damaging my root system and ultimately killing me. You must seek out a fertilizer specifically formulated for Australian native plants, which will have a low or zero phosphorus content (look for a ratio like 3-1-2 or 4-1-4). A light application in early spring and perhaps again in mid-summer is all I need. Over-fertilizing, especially with the wrong food, will harm me.
Once established, I am remarkably drought-tolerant. However, to help me establish a deep and robust root system in my first growing season, I need regular, deep watering. Please water me deeply once or twice a week, allowing the water to penetrate far into the soil, and then let the soil dry out almost completely before watering again. After my first year, I will only need supplemental watering during periods of extreme or prolonged drought. My leaves will tell you if I am thirsty, becoming slightly limp or less glossy.
I naturally form a dense, rounded shrub, but I appreciate light pruning to maintain my shape and encourage even more of my spectacular blooms. The best time to groom me is immediately after a main flush of flowers begins to fade. Please use clean, sharp secateurs and simply tip-prune the stems, cutting back by a few inches to a healthy set of leaves. Avoid hard pruning into old, woody growth, as I may not regenerate from these areas. My spent flowers can be deadheaded, but it is not strictly necessary as I am a self-cleaning cultivar.
