From our perspective as azaleas, winter is not merely a season but a physiological challenge. Our broad, evergreen leaves (for most varieties) continue to lose moisture through transpiration, especially on sunny or windy days. However, when the ground is frozen, our root systems cannot uptake water to replace this loss, leading to a condition known as desiccation. This is often more damaging than the cold itself. Furthermore, the water within our cells can freeze, forming sharp ice crystals that rupture cell membranes and cause irreversible damage to our tender tissues, particularly on new growth and flower buds set for the spring.
Your assistance in late fall is crucial for our survival. Please cease fertilizing us by mid-summer. Fertilizing too late encourages a flush of tender new growth that has no time to "harden off" or acclimate before winter arrives. This new growth lacks the protective compounds and cellular changes that allow older wood to withstand freezing temperatures, making it exceptionally vulnerable to the first hard frost. Instead, ensure we are well-hydrated throughout the autumn by providing deep, thorough waterings right up until the ground freezes. A well-hydrated plant is far more resilient to cold and desiccation.
The most critical protection you can offer is to our roots. Applying a thick, 3-4 inch layer of organic mulch (like pine bark, pine needles, or shredded leaves) around our base acts as a insulating blanket. This layer moderates soil temperature, preventing the rapid freeze-thaw cycles that can heave us out of the ground and damage our delicate feeder roots. It also conserves crucial soil moisture. Be sure to keep the mulch a few inches away from our main stem to prevent moisture buildup and potential rot.
For our evergreen varieties, the drying winter wind and intense winter sun are our greatest foes. They dramatically increase the rate of moisture loss from our leaves. Erecting a physical windbreak on the windward side (often north or west) using burlap screens or snow fencing can break the wind's force. In areas of intense sun, you may also construct a simple burlap screen or shade cloth on the sunny side to protect us. Avoid using plastic sheeting directly on the foliage, as it can trap excessive heat on sunny days and then rapidly freeze, causing more harm than good.
Our roots in containers are completely exposed to the ambient air temperature and are therefore infinitely more vulnerable than those planted in the ground. The entire root ball can freeze solid, which is often fatal. The best strategy is to move our containers to an unheated garage, shed, or protected porch for the winter. If we must remain outside, please group our pots together in a sheltered location and insulate them heavily by wrapping the pots with bubble wrap or burying the entire pot in a mound of mulch or soil to simulate the protection of an in-ground planting.
