I’ve seen similar posts about this problem so I’m really not sure if it addresses my particular problem. I had stone containers built and I planted cedars in these containers last spring. They did well all of last year but now after the winter, the cedars have turned brown and when I rub my hand over them, lots of needles fall off. I’m not sure if they’re alive or not. I do get lots of wind in that location, so I wrapped them up in burlap and made an additional covering over them as a type of tee-pee with long sticks. This location also gets full sun in the afternoon. That’s one issue. The other issue is if they’re not surviving is it due to the containers? The size of the containers are about 2 feet by 2 feet and go into the ground. The previous year I had boxwoods and they didn’t survive. I need help in determining if my cedars are dying (I picked cedars because I thought they would be pretty hardy), and if they are dying, what else I could possibly put in these containers that would give me a similar look as the cedars. Any advice you can give me would be greatly appreciated. Thanks very much
It is possible to grow cedars in containers in Toronto, although depending on the particular conditions in the winter and the size of the containers, cedars might not survive the winter. Given the harshness of the winter this year, it is not surprising that your cedars have browned. If the whole tree is brown and the branches are dry, it is likely that it did not survive; however, if the cedar only has brown patches and only some dry limbs, these can be pruned and new growth should develop. If your cedars have survived, you should ensure that they are kept moist throughout the summer. This can be especially difficult in containers which dry out more quickly than the soil in the ground. You should water them regularly until the soil is quite moist, although not sodden. You could consider a dripper hose to ensure adequate moisture to the roots. As well, fertilize in the spring with a time released evergreen fertilizer. If you intend to keep your cedars in the 2 feet by 2 feet boxes for a number of years you might have to prune the roots, so that the they do become root bound in the containers. When wrapping the cedars for winter make sure that the burlap is not touching the foliage and that they are well watered up to freeze up.
Here is a links to a useful article on growing evergreen trees and shrubs in containers, including which are most suitable: https://www.icangarden.com/document.cfm?task=viewdetail&itemid=7759, and a previous Master Gardener question on this issue: https://www.torontomastergardeners.ca/index.php/askagardener/blue-holly-and-cedar-shrubs-can-they-overwinter-in-pots/