From our perspective as Grevillea plants, we are resilient but have specific needs. When we appear to be dying or unhealthy, it is a distress signal, a response to conditions that are at odds with our fundamental requirements for survival. Our decline is rarely due to a single factor but a combination of stresses. To help us recover, you must understand and address these core issues.
First, observe us carefully. Are our leaves yellowing, browning, drooping, or falling? This is our language. Yellowing leaves often signal waterlogged roots or a nutrient deficiency, particularly iron, which we are very sensitive to. Browning or "scorched" leaf tips can indicate fertilizer burn from high-phosphorus feeds, which are toxic to us. A general wilt can mean either severe drought or, paradoxically, suffocating roots from too much water. Check the soil moisture an inch below the surface; we prefer it to be moist but never soggy.
Our most common ailment is being loved too much with water. We are deeply susceptible to root rot fungi (like Phytophthora) that thrive in consistently wet, heavy soil. If our roots are brown, mushy, and smell foul, they are drowning and dying. You must improve drainage immediately. For potted specimens, repot us into a very coarse, free-draining mix designed for native plants. In the ground, consider raising the bed or amending the soil with gravel and sand. Conversely, if we are bone dry, give us a deep, thorough watering to reach our entire root zone, then return to a cycle of letting the soil dry out slightly between waterings.
Please, never use standard fertilizers on us. Our roots cannot process high levels of phosphorus; it slowly poisons us. Use only a native plant or low-phosphorus (P) fertilizer, or a specific grevillea food, applied sparingly in our active growth periods (spring and autumn). Also, ensure we are receiving adequate sunlight. We are sun-worshippers. Without at least six hours of full sun daily, we become leggy, weak, and susceptible to disease. Furthermore, protect us from harsh, cold winds and heavy frosts, which can cause severe leaf burn and dieback, making us look unhealthy.
If we have extensive dead or diseased growth, a careful prune is necessary. This helps us redirect our precious energy into producing new, healthy growth. Use sharp, clean secateurs. First, remove all clearly dead wood, cutting back to a healthy side branch or bud. Then, lightly tip-prune the remaining healthy branches to encourage bushy regeneration. Avoid heavy pruning into old, bare wood, as we sometimes struggle to reshoot from these areas. The best time for this restorative pruning is in spring as the weather warms, giving us the entire growing season to recover.
