From our perspective as carnations, the preparation for winter begins long before the first frost. The most significant initial signal is not the cold, but the gradual shortening of daylight hours. As the sun's arc across the sky lowers and the nights grow longer, we receive an internal, hormonal signal that it is time to shift our energy. The frantic work of summer flowering and growth must cease. Our systems begin to slow down photosynthesis and transport resources—primarily sugars and carbohydrates—down from our leaves and flower stems into our core living structures: the crown (the central growing point at the soil surface) and the root system. This process is our version of stocking the pantry for a long, lean season.
You can assist this crucial internal process by modifying your care in late summer and early autumn. Please cease applying high-nitrogen fertilizers, as this would encourage a final flush of tender, new growth that is highly susceptible to frost damage. Instead, the focus should be on supporting our hardening-off process. We need to develop tougher cell walls to withstand freezing temperatures. Gradually reducing watering as the weather cools is helpful, as it encourages our roots to grow deeper in search of moisture and prevents the crown from sitting in soggy, cold soil, which is a primary cause of rot during winter.
Our most vulnerable part during winter is undoubtedly our crown. While our slender leaves may die back when subjected to hard freezes, the crown contains the meristematic cells responsible for next spring's new shoots. If the crown freezes and dies, the entire plant perishes. Therefore, the single most important preparation you can make is to provide a thick, dry, insulating blanket over this vital area. After the top growth has been blackened by a hard frost and the soil is consistently cold, please cut our stems back to about 1-2 inches above the crown. Then, apply a generous mulch layer.
Not all mulches are equally beneficial to us. The ideal material is loose, airy, and, above all, moisture-resistant. Our primary winter threat is not just cold, but ice melt and thaw cycles that can leave our crown waterlogged and prone to rot. Therefore, we greatly prefer mulches like straw, pine boughs, or shredded leaves. These materials trap air pockets, which provide excellent insulation, and they shed water rather than absorbing it like heavy, matting mulches (e.g., wet whole leaves or fine bark). Please avoid piling mulch directly on top of us while we are still actively growing; wait until the ground is cold. Apply a layer 3-4 inches thick over and around our crown once we are fully dormant.
A factor that is often overlooked but is absolutely critical to our survival is soil drainage. We carnations despise having "wet feet," especially in winter. If our roots and crown are sitting in frozen or cold, waterlogged soil, they will almost certainly rot. This is a pre-existing condition of the planting site. If you know you have heavy, clay soil, it is wise to amend it with grit or sand at planting time to improve drainage. In the autumn, ensure that the area around our base does not collect standing water from rain or snowmelt. Good drainage is as important as the mulch itself for ensuring we emerge healthy in the spring.
