Winter Tips

Juggling Your Safety with Eco-Safety

Remember not to use fertilizers, such as urea, as ice melts on your driveway and sidewalk areas.  First, it is now against the law in Maryland to do that, as the fertilizer will likely wash into the street storm drains and promote nitrogen-induced “algae bloom” that will hurt the Chesapeake Bay plants and wildlife. 

Winter Pest Control

Insect pests and mites that find they cannot live or stay active in extreme outdoor cold find a new lease on life by moving indoors and then will turn their full attention to your houseplants.  Keep an eye on houseplant health and be sure to treat any pest problems you encounter as soon as you discover them.  Be sure to use pesticides that are safe to use indoors and please be sure to read and follow all directions and caution for their use.

Winter Plant Damage 

With the extremely cold temperatures and wind chills, winter garden problems are most likely to occur.  Be out and about in your garden frequently to see if any broadleaf evergreen shrubs are experiencing cold damage to their leaves and branches or if recently-installed container plants are not experiencing “heaving.

What Do I Do With Shrubs Affected by Winter Freeze Damage?

Winter can present us with some unusually frigid day and night temperatures.. We know that the last week of February and the month of March is the time to prune back many of our shrubs and trees. However, for those evergreen broadleafed plants that have kept their green leaves through this especially cold winter, many of the plants are showing more severe freeze burn damage on their leaves and branches than normal. We have received many inquiries from area gardeners who have such damage on their euonymus, magnolias, camellias, photinias and other similar shrubs. They are asking for guidance as to knowing when the damage they see is beyond the point of saving the plant. These are my recommendations for addressing their cold-damaged plant situations.

First, do not assume the worst. Much of the damage may be confined just to the leaves and not to the stems that support them. If this is the case, the healthy stems will be able to replace the dead and damaged branches and leaves as the spring season progresses. 

healthy-cambium-layerCheck the health of the cambium layer that lies just underneath the bark of the branches. Make a small scrape in the bark with your thumbnail and see if the cambium is still a green color. If it is, the branch is alive and will be able to replace the dead and damaged leaves with new ones. If the color of the cambium at the scrape is yellow or brown, it means that the branch at that point is dying or dead. Then, do other scrapes lower down on the same branches until you come to where the green cambium shows. Prune back the branch where the green cambium begins above the nearest outward-pointing leaf. If the cambium is not green all the way down to the base of the branch, then the whole branch should be pruned off.

If more than 50% of a plant’s main branches are shown to be dead by this procedure, then I recommend its removal and the planting a new plant in its place.