From my perspective as a Grevillea, light is my fundamental source of energy. If I am not growing, it is likely because I am not receiving sufficient sunlight to power my internal processes. I am a sun-worshipper by nature, requiring a minimum of six hours of direct, unfiltered sunlight each day. When planted in too much shade, my photosynthetic factories (my leaves) cannot produce enough sugars (photosynthates) to support new growth. The energy I do produce is diverted solely to basic survival, leaving nothing in reserve for producing new stems and leaves. You might notice my form becoming leggy as I stretch pathetically towards any available light source, a clear sign of my desperation.
My roots are exceptionally sensitive to waterlogging. I am adapted to well-drained, aerated soils, and my root system absolutely requires oxygen to respire and function. If I am planted in heavy, clay-based soil that remains constantly wet, my roots are effectively suffocating. In this oxygen-deprived state, they begin to rot and die. Without a healthy root system, I cannot uptake the water and nutrients from the soil that my upper parts desperately need. This root rot is a silent, underground crisis that manifests above ground as a complete halt in growth, yellowing leaves, and a general decline in my vitality.
The chemistry of the soil around me is critical. I thrive in slightly acidic to neutral soil pH. If the soil is too alkaline, it chemically locks up certain essential nutrients, particularly phosphorus and iron, making them unavailable for my roots to absorb. Even if these nutrients are present in the soil, I cannot access them. A phosphorus deficiency severely limits my ability to transfer energy and develop new tissues, while an iron deficiency leads to chlorosis—yellowing leaves with green veins—further reducing my photosynthetic capacity. Furthermore, I am highly sensitive to phosphorus; excessive levels from standard fertilizers are actually toxic to me, burning my roots and compounding the growth problem.
Your watering routine could be a significant stressor. While I am drought-tolerant once established, my initial establishment phase requires consistent moisture. If I am allowed to dry out completely and repeatedly when young, my tender new roots die back, creating a cycle of setback that prevents me from growing. Conversely, as established, my dislike for "wet feet" is paramount. Frequent, shallow watering that keeps the topsoil perpetually damp encourages weak, surface roots and does not promote the deep, robust root system I need to seek out resources and support vigorous top growth. The resulting stress from both under and over-watering forces me into survival mode, not growth mode.
Finally, I may simply have run out of space. If I am growing in a container, my roots may have exhausted the available soil volume and become pot-bound. This creates a dense, circular mass of roots that cannot effectively uptake water or nutrients, severely stunting my growth. In the landscape, I might be facing competition from the roots of larger, more aggressive trees or shrubs that are outcompeting me for water and soil nutrients. Without adequate space and resources to call my own, my expansion is physically impossible.
