Caring For Dormant Trees
Trees are survivalists, as is all of nature. If anything begins to threaten them, they adapt or change. For trees in the winter, dormancy is the solution to conserving energy and surviving. What is dormancy? It is a period when the tree’s physical life cycle is temporarily stopped to help the tree minimize metabolic activity. There are different types of dormancy.
One type of dormancy is called Predictive Dormancy, this occurs when a tree enters a dormant phase before the weather changes – for instance, before it begins to freeze or get cold. There is also Consequential Dormancy, this occurs when a tree goes into dormancy after outside conditions have occurred. Consequential Dormancy occurs often in places where the climate is unpredictable.
The life of a tree occurs in cycles. In early spring, as days begin to bet longer and the weather is warmer, the tree is pulling all of its energy together for growth. This is when a tree puts off its seeds. Some trees produce flowers, from which the seeds come, before the leaves come out in the spring. These flowers produce seeds that ripen in the spring and fall to the ground and start to grow that year. Other seeds ripen and drop off in the fall and lay dormant over the winter and start to grow the following spring. In order for any seed to sprout and develop it must have food, water, sunlight and warmth. Until it gets roots, a stem above ground, and some leaves or needles, the seed uses the food stored in its shell to develop growth. As roots go deeper into the soil they absorb water and minerals form the soil and send these up into the stem.
As the weather continues to warm and summer arrives, the tree begins to grow rapidly taking advantage of the long days and optimum sunlight. For most trees, growth ceases by late summer (early August). That is, the tree does not produce any more leaves after this time. From this point until fall, the objective of the tree is to prepare for winter. During fall, a tree stores up food and energy reserves everything that is needed for next spring’s growth.
The shorter days, cooler temperatures and reduction in sunlight then stimulates dormancy in the tree. During dormancy a tree may look dead but it is far from it. It is only waiting for spring. Changing the conditions around the tree may alter the time of year that the tree goes into dormancy. Heavy watering and fertilizing in fall (September) may stimulate the tree to continue growing, but this is not recommended. Any new growth produced at this time of year will have little chance to prepare itself for winter, and will most likely die from winterkill.
As winter finally sets in, the tree will then become fully dormant. Trees still continue to slowly grow roots, respire and take in water and nutrients throughout the winter. Many dormant trees have to be protected to keep it free from disease and insects. Caring for your tree before it goes into dormancy such as pruning it in late fall will help form and strengthen your tree as well as encourage new growth in the spring. Pruning also minimizes storm damage.
Mulching your tree in the winter is also helpful to the tree as it protects its feeder roots. If you are in a region that receives a lot of rain or snow, you may also want to consider aerating the soil around the tree so it doesn’t become waterlogged. It is critical not to damage tree roots in the soil as you do this so work only on those few inches at the surface crust. ??
If you are in an area that receives little rain, be sure to water your tree throughout the winter. Your tree won’t need as much water but nonetheless will need moisture.
A tree is a strong organism but can be stronger with a little help along the way, even in the winter.