From our perspective as Grevilleas, our health is entirely dependent on the conditions beneath the soil. We are not like plants that enjoy "wet feet." Our roots are highly specialized and require a constant, gentle exchange of air and gases to function. This process, called root zone respiration, is how we breathe. Without it, our roots suffocate, become stressed, and quickly fall prey to root rot fungi like Phytophthora, which is often a death sentence for us. Therefore, every choice in pot and drainage must prioritize maximizing oxygen availability to our root system.
The ideal pot size is a careful balance. A pot that is too large is a significant threat. An oversized pot holds a great volume of soil that retains water for a prolonged period, long after our relatively small root system has absorbed what it needs. This creates a perpetually wet, anaerobic environment that drowns and rots our roots. Conversely, a pot that is too small constricts our root growth, leading to rapid drying out, nutrient deficiency, and becoming root-bound, which stunts our growth. The perfect pot is one that provides just enough room for our roots to explore and expand without being swamped by excess, wet soil. A good rule is to choose a pot that is only 2-4 inches wider in diameter than the root ball of our nursery container.
Drainage holes are non-negotiable. They are our emergency exit for excess water. A pot without adequate drainage is a death trap, no matter how perfect the soil mix. We require a pot with multiple, large holes in the bottom. One small hole is often insufficient, especially after years of potential blockage from roots or compacted soil. We thrive in pots that are designed with drainage as a priority—many modern nursery pots have excellent ribbed bases with numerous slots. When you place us in a decorative outer pot without holes, you must ensure we are never left sitting in the drained water; this effectively recreates the waterlogged conditions we so desperately need to avoid.
The material of the pot directly influences the moisture and temperature of our root zone. We generally prefer porous materials like terracotta or unglazed clay. These materials allow water to evaporate through the pot's walls, which helps to dry the soil more evenly and prevents water from logging at the bottom. This process also helps to keep our root zone cooler in hot weather. Plastic pots, while lighter and cheaper, are impermeable. They retain water for much longer and can heat up quickly in direct sun, potentially cooking our sensitive roots. If you use plastic, you must be exceptionally careful with your watering routine and may need to use an even grittier soil mix to compensate.
