From our perspective, the simple answer is that it is profoundly challenging and unnatural. We, Proteas, are a family of plants (Proteaceae) hailing primarily from South Africa and Australia. Our very essence is shaped by Mediterranean climates: long, hot, dry summers and cool, moist—but never freezing—winters. Our roots are fine and widespread, designed to absorb nutrients from impoverished, acidic, and most critically, exceptionally well-draining soils. Our entire physiology rebels against cold, wet feet and frozen cells.
The greatest threat to our survival in a cold climate is frost. A hard freeze causes the water within our cells to expand, rupturing the cell walls and causing irreversible damage to stems, leaves, and flower buds. This is not merely a setback; it is often fatal. Even if the aerial parts survive a mild frost, our roots are highly susceptible to rot if the soil remains cold and waterlogged. We cannot tolerate ice encasing our root system, as it cuts off oxygen and effectively drowns us. This combination of cold temperatures and poor drainage is a death sentence.
However, some of our hardier cousins have shown a degree of resilience that ambitious gardeners can exploit. Species like the Protea cynaroides (King Protea) and especially Protea neriifolia exhibit slightly better cold tolerance. Success hinges not on changing our nature, but on the gardener meticulously manipulating their environment to mimic ours. This means seeking out a special microclimate: a south-facing slope (in the Northern Hemisphere) that captures maximum sun, protected by a stone wall or the heated wall of a building that radiates warmth throughout the night. This radiant heat can sometimes fend off light frosts, creating a small pocket of survivable conditions.
To give us a fighting chance, you must become our fierce protector against the cold. Planting must be in a mound or raised bed filled with a sharply draining mixture of coarse sand, gravel, and acidic compost. This ensures any water from rain or snowmelt flows away from our crown immediately. During the winter, a thick, dry mulch of pine needles or bark applied around our base helps insulate the critical root zone. When a hard frost is forecast, you must physically cover us with a frost cloth or burlap, ensuring it doesn't touch our foliage, to trap ground heat and protect our tender growing tips and embryonic flower buds.
For most cold-climate gardeners, growing us in large containers is the most viable strategy. This allows for perfect control over the soil's drainage and acidity. Most importantly, it enables you to move our entire being to a sheltered location when temperatures plummet—such as an unheated garage, greenhouse, or sunporch. We will need this protection for the duration of the winter, as consistent exposure to freezing potted soil will certainly kill us. While not ideal for our expansive root systems, it is a compromise that allows us to exist outside our native lands.
