I have several plantings of the narrow arborvitae ‘Emerald.’ During this past winter and especially with the late spring snow fall, they have become bent over about midway up, even though we shook off the snow-laden branches. Is there anything I can do now to help them return to their straight, upright growth habit?
Due to their multi-stemmed nature, arborvitae and junipers are especially susceptible to having their limbs distorted from heavy snow loads. These loads cause the branches to bend and separate from the center of the plant. If the snow load is heavy enough, the branch can break.
Snow should be removed as soon as the storm stops by either using a broom to jostle the branches, gently shaking the tree so as not to damage the bark or by sweeping upwards. In case the weight of the snow has severely bent an individual branch, try re-positioning it by tying it to other branches within the shrub.
In more severe cases, like with yours, you can attempt to straighten them by tying a soft rope (their bark is thin), even old panty hose or stockings will do, around the trunk. You will need to tie above and below where it’s bent. Attach a rope to that and pull the tree straight. You will have to anchor the rope and leave it on for at least 6 months if they have been bent for a while. There is no guarantee that they will straighten, but it’s worth a try.
Evergreens can be protected from snow breakage by tying the branches together with strong rope or twine before winter snows are expected, but after the first severe frost. Fasten it near the tip of the tallest branch and then spiral down around the entire tree and tie it off to the base. You do have to remove it at the first sign of spring.