From my perspective as a Grevillea, the concept of "cold" is fundamentally alien. My roots, stems, and leaves are engineered for sun-drenched, well-drained, and warm environments. My vascular system is designed to move water and nutrients efficiently under the warmth of the sun. When temperatures plummet, the very water that gives me life becomes my greatest threat. Ice crystals can form within my cells, causing them to rupture and die—a death sentence for my tender foliage and young stems. My primary need is not just to survive above ground but to protect my crown and root zone, the very heart from which I will regrow.
Your most crucial decision is where you place me. I crave the sun's radiant heat, even in winter. Please plant me or position my container in a location that receives maximum sunlight exposure, ideally a south-facing wall if you are in the northern hemisphere. This wall acts as a thermal mass, absorbing heat during the day and gently radiating it back to me throughout the cold night, creating a precious microclimate. Furthermore, this spot must be shielded from punishing, desiccating winds, which can rapidly strip moisture from my leaves and cause severe windburn, exacerbating the cold damage.
My relationship with water becomes precarious in winter. My soil must be exceptionally well-draining; saturated, cold roots will quickly succumb to rot. Please ensure my bed is mounded or my pot has ample drainage holes. However, I am not dormant. An entirely desiccated root system is also vulnerable. Before a deep freeze is forecast, provide me with a deep, thorough watering. This hydrates my cells, making them slightly more resilient to freezing, and the moist soil retains heat better than dry soil, offering a buffer to my roots. Thereafter, water me only during a mild spell when the soil is dry several inches down.
You can replicate a milder climate around me. After the first hard frost, apply a very thick, loose layer of mulch—like bark chips or straw—around my base. Pile it high, covering my crown and root zone. This blanket does not heat me, but it insulates me, stabilizing the soil temperature and protecting my vital roots from freeze-thaw cycles. For my upper body, a blanket is not enough. When a hard freeze is imminent, construct a simple frame around me and drape it with breathable fabric like burlap or a frost cloth. Never use plastic, as it can trap excessive moisture and cook me when the sun appears. This tent traps the geothermal heat rising from the ground, keeping the immediate air around me a few critical degrees warmer.
I know my vibrant growth is tempting to nurture, but you must resist fertilizing me in late summer or fall. Any application of high-nitrogen fertilizer will encourage a flush of tender new growth that is extremely susceptible to cold damage. This new growth diverts my energy away from hardening off my existing stems and roots for winter dormancy. Allow me to naturally slow my growth as the days shorten. Furthermore, avoid any significant pruning in autumn. Pruning can have the same effect, stimulating new growth at the worst possible time. Save any shaping cuts for the spring, once all danger of frost has definitively passed.
