Why Is My Tree Dead?! Winter Burn Facts and Remedies
by Marissa L. Tomasic
Your once healthy boxwood hedge is looking brown and dry. The beautifully shaped holly you bought last summer is now looking sparse and brittle. Even your ten year old spruce has brown tips on it's branches. Why are all your plantings dying?!
Fear not, your trees and shrubs are probably not dying or dead, they have only suffered a bit of dehydration known as Winter Burn. Winter Burn is very common in New England and especially common after a long, cold winter like the one we had this year. Winter Burn, or desiccation, occurs when the ground freezes and a plant's roots are not able to take up water. Plants continue to loose water through pores (stomata) on their leaves and stems, and if they are not able to take up water from their roots, dehydration occurs. Cold, drying winds exacerbate the problem. Winter Burn begins to show once temperatures begin to increase, and continues well into the spring. If your trees or shrubs have brown leaves and brittle stems, generally on the tops and outer edges of the plant, it is most likely Winter Burn. So what should you do?
Firstly, be patient. Plants are well equipped to handle some stress and will generally revive themselves once their conditions become favorable and they have some time to overcome damage. It is also advisable to wait another few months to see the full extent of the plant's damage. Most plants need to have their first flush of growth (new leaves emerging) in order to recover from Winter Burn. Before making any determinations about the health of your plant, wait until mid-June. Once you are able to assess the full damage, steps can be taken to help them along in their process and to make your plantings look more appealing to you.
Feel free to trim off any stems and leaves that are completely dead. This isn't necessary for the plant but more for the plants admirers who don't like the look of browned branches and leaves. If left alone, dead leaves or needles will simply fall off once the plant begins its growth stage. If you decide to trim or prune, be sparing on your cuts. Cut only branches or leaves that are completely dead. (Dead branches will have leaves that are completely brown, and the branches will be very brittle, snapping apart easily when you bend them.) Cut just below dead sections of any branch.
Water thoroughly. Most trees and shrubs benefit from a twice-weekly watering. Ideally you should water from the trunk to the drip line, applying a small trickle of water for about an hour. Short, frequent watering sessions do not allow water to get deep enough into the soil. Soaker hoses are a great way to water trees and shrubs. Otherwise a standard hose with a small stream of water placed at the base of the plant will be sufficient. Newly established plantings require more water from you than their well established counterparts. Water twice weekly for the first full year after planting trees, shrubs or perennials.
Organic fertilizer should be applied once now and once again in the Fall. (We recommend Espoma Holly Tone for most trees and shrubs.) Plants benefit from the slow release of organic fertilizers as they break down in the soil. Apply the amount recommended on the bag, scratching the fertilizer into the soil around the drip line.
Road salt can also add to winter dehydration, as it draws additional water away from plant's roots. If you have plants near a roadway and you suspect salt damage, simply water the area (again, slowly and for long periods) and the water-soluble salts will wash away. Adding garden Gypsum will aid greatly with salt damage, as it reduces soil compaction thereby increasing drainage. It also has the ability to dislodge sodium in soil, allowing it to wash away.
Going forward, protect plantings from Winter Burn by wrapping them in burlap after applying an anti-desiccant spray in late fall, plus applying that fall feed of an organic fertilizer. Try to get new or transplanted plants in the ground by late September so the roots have a chance to establish themselves before the cold weather comes. Also carefully consider the placement of plantings; a place that receives high winds and full sun may not be a good spot for a young tree or shrub.
Always feel free to call or come by our Nursery if you have any questions about Winter Burn or plant care in general. And remember to be patient when dealing with plants. Nature does not regard our fast-paced timelines; its splendor is an ever evolving process that we are lucky to witness a small part of.