Most plants in most parts of the country, at least during the winter months, lose their leaves, turn brown and seem to stop growing. The main reason is that they are just plain tired. After a long growing season where they put on new growth and flowers and set seeds, plants are exhausted, drained and tuckered out. Though they may appear dead, many plants are merely dormant. Ornamental grasses, for instance, look dead on top of the ground, but below ground the root system is alive and well. When conditions are right, the grass will start to grow again. Here are a few tips to better understand how dormancy works:
- Dormancy is like a form of hibernation for plants. Just like a bear eats a lot to store up fat before it hibernates, plants convert most of the elements in fertilizer into carbohydrates, which they can use to sustain themselves during dormancy. For that reason, it is a good idea to fertilize a number of plants just before they go dormant and while they are still green.
- There are different degrees of dormancy. A hackberry, for instance, may be completely dormant, having shed all its leaves and shut down all but the basic biological processes needed for survival, while pine trees remain in a semi-dormant phase during the winter months. Remember, many trees are best planted during their dormant season, because they are a lot less likely to suffer from transplant shock. Without their leaves, they cannot lose moisture and dry out.
- There are all sorts of plants that are stuck in the ground during their dormant phase such as asparagus, potatoes and seeds. Dormancy and seeds are fascinating because seeds can lie dormant for decades. Seeds have all it takes to get up and grow, but unless certain conditions are met they just sit. Those conditions include sufficient moisture, and in some cases light and temperature. Mechanical abrasions such as a seed being tossed about the wind or washed about among rough soil particles may also instigate growth. This explains why many of the tricks we use to make seeds germinate work so well--such as placing seeds between moist paper towels or cooling them in the refrigerator. Scarification (slitting or softening the outer coat of seeds to speed germination) is one tactic that works well with spinach or beets.
- Above-ground plants are forced into and out of dormancy by those same conditions--moisture, light and varying degrees of temperature. While the weather does play a role in inducing and breaking dormancy, it does not always do so directly. For example, many plants respond not so much to the arrival of warmer or colder temperature but to changes in day length accompanied by the changing seasons. It is important to realize that dormancy is not strictly a fall or winter phenomenon. Turf grasses like Bermuda may brown and go dormant in the middle of summer, for instance; that is in response to extreme heat. But it will bounce right back as soon as temperatures cool off a bit. Again, it is simply the plants way of saying, "Hey I'm tired and need a break."
