As the plants become dormant and hibernation falls on the land, I become aware of how automated the ecosystems are. Despite the harsh winter conditions headed our way, native plants are prepared for the weather both physically and morphologically. I am always amazed by how cold hardy plants do not freeze and or die in the winter. If plants are comprised of so much water, how do they not freeze solid or burst apart? It all comes down to chemistry. As temperatures begin to drop, plants convert their starches to sugar and move water to spaces between cells. So, when winter arrives, there is less water that can actually freeze in the cells. The high concentration of starches within the tissues is similar to throwing salt on ice. Think of it as plant anti-freeze. Spruce and other evergreen trees demand and retain even less water, making them naturally more freeze resistant, even in the root zone. This allows roots to undergo extreme freezing conditions without negative effects. For example, in our nursery area, we keep our red spruce outside in pots all year with great success. In fact, last year they were covered by over 2 feet of snow for weeks with no damage!
We are now applying composted horse manure to our beds and plant crowns. This allows for a slow release of nitrogen all winter. Composted manure and other forms of compost also contain calcium. Calcium is vital for plants to form new tissue. In general, organic matter has calcium in its makeup. Woody debris, including wood chips and rotten wood/sticks, as well as leaves all have calcium. If added to our plants during the winter, then we will see increased growth in the spring. This is a trick fruit growers use to produce larger fruit sizes. Our woody plants show a lot of improvement in growth response after only a few yearly topdressings. It really is remarkable that a “waste” product fairly low in nitrogen but high in organic matter can outperform a pelletized chemical fertilizer. Perennial beds can also benefit from topdressing. But if they are plants you commonly have to stake, go lightly with fertilizers, including manure, to prevent leggy elongated growth and eventual toppling of the stems. On the whole, ferns, wildflowers or native woodland plants do not need fertilization either. They get the nutrients they need from rain drops “catching” nitrogen in the air and delivering it to the soil surface. We do not apply any nitrogen or manure to our wildflower labyrinth for this reason. However, some soils are deficient or excessive in nutrients by nature, therefore, soil testing is always a great first step. Your local county extension agent can assist you with this and help you determine the right amount of nitrogen, phosphorous, and potassium to add.
Be on the lookout for winter injury caused by wind and rapid temperature change, such as a polar vortex. Antitranspirants are liquid sprays that can be applied to the leaves and stems of plants to protect them from winter damage. The antitranspirant forms a protective layer that helps the plant retain water in its leaves and buds. One of the worst cases is when the ground is frozen, and the air temperature rises during the morning long before the ground will thaw. This disparity causes the plant shoots to lose too much water and prevents the frozen roots from releasing water to replenish it. This process is called desiccation and leads to winter injury or winter burn. In areas with a longer winter, antitranspirants may need to be applied twice. For example, we spray broad leaved evergreens like Rhododendron ‘English Roseum’ with TransFilm in late fall and early spring, making sure to coat both sides of the leaf.
While our landscapes hibernate, there is still much to do in our gardens. With the perennials tucked away and the leaves no longer shielding our view, the bones of the garden are at their most noticeable. This is the time for mentally readying ourselves for the next stage of life in the garden and planning ahead for what’s to come. Winter allows us to forget our failures of the year before and to believe that next year, for sure, it’s all going to work out — there will be no weeds, no drought, no pests and disease, no dead as a doornail $29 plants. Winter is a time of recovery, preparation, and hope.