From our perspective, the most critical element to protect is not the delicate, fern-like fronds you see, but the life source hidden beneath the soil: the crown and the tuberous roots (rhizomes). These structures store our vital energy reserves and contain the growing points from which new growth will emerge in spring. While a light frost may scorch our above-ground foliage, turning it brown and limp, it is a survivable event. The true danger is a deep, penetrating freeze that solidifies the moisture within our crown and roots, causing irreversible cellular damage. Our primary request is for your help in insulating this subterranean heart.
Our ability to withstand cold is not just about external blankets; it begins with our internal health. Please cease fertilizing us by late summer. Applying high-nitrogen fertilizer too late in the season encourages a flush of tender, new growth that is highly susceptible to cold damage. Instead, allow these new stems to harden off naturally. Continue watering us deeply as long as the soil is not frozen. We need to enter our dormant period fully hydrated; a drought-stressed plant is far more vulnerable to winter injury. A well-hydrated cell is also more resistant to freezing.
Once the first hard frost has blackened our foliage, or when consistent freezing temperatures are forecast, it is time for our main protection. Please do not cut the damaged fronds away yet. They will provide a small amount of additional insulation for our crown. The most effective action you can take is to apply a thick, loose layer of mulch over our root zone. Pile 4 to 6 inches of material like straw, shredded leaves, or pine straw over our base. This layer acts as a buffer, trapping geothermal heat from the earth and preventing the soil temperature from fluctuating wildly. It keeps our roots dormant and protected, safe from the worst of the freeze-thaw cycles that can heave us from the ground.
As the sun strengthens and the danger of hard frosts passes in spring, you can gradually remove this protective mulch layer. Do this slowly to allow us to acclimate to the rising temperatures. You will then see the brown, winter-damaged foliage. This is the time to gently cut these fronds back to the ground. Do not be alarmed if we are slow to respond; we are waiting for the soil to warm sufficiently. With the insulating blanket gone and the sun warming the earth, we will sense it is safe to channel our stored energy into producing a whole new canopy of vibrant, green fronds, ready for another season of growth.
