David YostHow To Prevent Winter Damage
During the winter season when many of your outdoor trees, shrubs and container plants are dormant, it’s important to be aware of the steps you can take to keep them healthy during the winter. Desiccation, when plants dry out too much, is the most common issue that we see with our customers’ plants. This will occur when a plant dries out completely due to wind gusts and lack of moisture in the air or soil. Knowing the signs of desiccation and understanding the steps you can take to prevent it will allow you to keep all of your plants healthy throughout the winter, even those that are most vulnerable in cold weather.
The Signs Your Plant is too Dry
If your plant’s leaf tips are turning brown, that is the first sign that your plant is dealing with desiccation. It is not too late for your plant, and you can take steps to save it! Winter damage of this type is most likely to affect broadleaf evergreens, trees and shrubs planted in the past year, container plants and any plant at the boundary of its viable gardening zone. In this guide, we’ve outlined the best ways to prevent winter damage for each of these kinds of plants this season.
Broadleaf Evergreens
These types of plants include camellias, gardenias, Southern magnolias, fig trees, hollies, rhododendrons and boxwoods. Camellias and Southern magnolias specifically have broad flat leaves with a large surface area, making them more susceptible to browning leaves than evergreens with smaller needles with minimal surface area. If these plants endure dry winds and winter sun and do not have sufficient snow or rain to provide moisture, they will dry out and develop brown leaves due to desiccation. In order to prevent these plants from drying out too fast, you can surround the trunk of your broadleaf evergreens with a triangle of burlap up to 18” tall and fill the enclosed area with oak and maple leaves. You can set up three poles surrounding the tree in a triangular shape and wrap the burlap around it, then add oak leaves into the bottom of the structure, insulating the roots to protect them from cold weather. If you have access to maple leaves, top the oak leaves with maple to assist with sealing in moisture in addition to insulating your plant’s roots.
As an additional step, or if you do not have access to burlap or extra leaves, another way to prevent your broadleaf evergreens from desiccation is to spray your plant with Wilt Pruf (which we carry here at Merrifield) to help the leaves seal in moisture and stay moist and healthy throughout the winter season.
Trees and Shrubs Planted in the Past Year
Trees and shrubs that you planted in your garden in the past year are particularly vulnerable to winter damage because their root systems are not fully established. One of the best ways to prevent your new plants from desiccating over the winter is to add three to four inches of mulch on top of the soil during the months of November and December. You can use bark mulch, pine straw or leaves to insulate the soil around the plant. Mulch will act as an insulator, much like putting a blanket over yourself, sealing in moisture and warmth.
You may find that critters like mice, rabbits and deer are also attracted to new and young bark of your trees and shrubs. If needed, you can wrap guards like plastic or wire around your plant to deter furry visitors from gnawing on the young plant material. Deer can also be an issue when food becomes scarce during the winter season, and so people who live in deer populated neighborhoods will need to take precautions to avoid having their landscaping browsed. You can check out our blog on deer deterrents here.
If you encounter a particularly dry winter, we recommend checking in on your new plants at least once a month to see if they need water. If you feel the ground and the soil seems dry, you can water the plant thoroughly with a hose or watering can, dousing the soil to make sure it is thoroughly watered. You can also stay updated with your area’s weather forecast to see if you are expecting snow or ice. If snowfall is on the radar, you won’t need to water as much, as the blanket of snow will melt and trickle into the soil.
Container Plants
Container plants are particularly vulnerable to cold because they do not benefit from the insulation provided by the soil in the landscape. Much like young trees, container plants also have a smaller root system and therefore will dry out faster than plants that have been established in the garden for a few years. There are a few ways to prevent your container plants from enduring desiccation and other winter damage. These recommendations range from insulating pots with burlap and bubble wrap to protect the plant’s roots to planting containers in the ground, bringing delicate plants inside and grouping plants together. If you’re interested in learning more about each of these options to keep your plants safe and healthy over the winter, you can check out our blog about overwintering containers.
Plants at the Boundary of Their Gardening Zones
Here in northern Virginia, we are in garden zone 7, but some plants like rosemary and pomegranate trees that are native to zones 8 to 9 will generally be fine with a mild winter, but might struggle if we have a severe winter. If you have plants in your garden that are native to the warmer climates of zones 8 and 9, these will be more delicate and vulnerable to winter damage like desiccation. If you wish to keep these types of plants outside during the winter, you can cover them with burlap or a horticultural fleece blanket to keep them from enduring too much wind that will dry the plant out. As these plants retain their foliage through the winter, it will be important to check on them at least once a month to see if they are receiving enough moisture.
Final Notes on Watering
All of your plants, no matter what category, can be checked on semi-frequently to see if they have enough moisture. If the ground is frozen and dry, you can water the roots thoroughly with a hose or watering can. Your plants will benefit from good drinks throughout the season. Having said that, if you regularly receive snow throughout the winter, the precipitation helps to insulate the plants and give them adequate water over time as it melts. Keeping up with the weather forecast will help you figure out if you need to water your plants or let them be.
If you need any help this season, please call our plant clinic and we will be happy to assist you.
