Wow! What a snow!!

After our recent beautiful but very heavy snowfall, we have been bombarded with e-mails and questions on the radio about what to do about damage caused by the buildup of snow and ice on evergreen trees and shrubs, and even some deciduous trees and shrubs as well.

Andre's advice ...

Don't do anything - yet!

His advice is to wait until the snow melts away and the weather warms a bit - then assess the damage. The snow damage is usually worse on evergreens because the foliage holds the snow on the branches. Often the outer branches of shrubs like boxwood, yew, and azalea become weighed down with snow, separated from the center, and pinned to the ground. If you try to remove the snow, you can do more damage to the shrub. Let the snow melt off naturally!

1. No Permanent Damage - Many evergreens are fairly resilient and will bounce back after the snow melts and regain their original shape (more or less). In this case, you won't need to do anything.
2. Minor Damage - Sometimes, after a heavy snow that stays around for a long time, the branches don't bounce back into place after the snow melts off. In this case, you can tie the branches back into place with sisal twine. Tie the shrub in 3 places to pull it back together; near the bottom, in the middle, and near the top (see diagram). Don't tie the twine too tightly. You will have to leave it tied like this for about a year, then you can cut the twine and remove it. This works well for an individual shrub but if you have damage like this to a hedge, there is a different process: drive metal fence posts along the hedge every 8-10' and stretch 2 or 3 levels of wire between them (depending on the height of the hedge) to pull the branches back up and hold them in place (see diagram). 
3. Minor splits or cracks in branches - If a smaller branch on a deciduous tree has split or cracked slightly and the damage isn't too severe, you can use first-aid tape or plastic electrical tape to hold it together. The cambium layers will knit together over time and the wound will eventually heal.
4. More severe splits at a crotch in the trunk of a small tree can be pulled back together by tying the two branches together above the split. The split can then be taped or for larger branches, you can drill a hole through the 2 branches and hold them together with a thin bolt with a large (1" diameter) washer at each end.
5. Broken branches and those severely damaged or split should be cut off completely. This should be done as soon as you determine that the branches cannot be saved. Keep in mind that removal of broken branches may necessitate additional pruning to re-shape the tree and make it look better.
6. To aid in their recovery, spray broadleaf evergreens with Bonide Wilt Stop and feed any damaged trees and shrubs with Holly-tone (or Plant-tone) once the snow is gone.

In the early spring, sometime in March, make a final assessment of winter injury on your trees and shrubs.

• If you have severe damage to boxwood, azalea, rhododendron, hollies, or yew, you may need to cut these back hard in March while they are still dormant. They can be pruned to 24"-36" from the ground if necessary. Watch Mark's video tip on how to do this with boxwood.
• Certain evergreens, such as Pinus (pine), Abies (fir), Picea (spruce), Thuja (arborvitae), and Juniperus (Juniper), cannot be cut back hard because there are few or no dormant buds in the bark. Luckily, in most cases, these are fairly "snow resistant" and tend to spring back into shape when the snow melts. Azalea, rhododendron, holly, yew, and boxwood all have dormant buds in the bark and when pruned will produce new growth from these buds (see above).
• After severe pruning, always fertilize your shrubs with Holly-tone (or Plant-tone), rock phosphate, and green sand following the Viette's recommendations.