Arborvitae (Thuja) may be Essex County’s most popular privacy tree. Arborvitae is Latin for ‘Tree of Life’ which was the name it was given for saving early sailors from scurvy. Apparently, the fragrant trees can be brewed into tea. These evergreens are native to North America and Asia and have been bred into many varieties for use as hedgerows and living fences. At maturity in the wild, they can get 50 feet tall, but most hybrids sold at the nursery for homeowners only grow to 20 or 30 feet tall.
Arborvitae likes full sun and is tolerant of most soil types and has few pest issues. The biggest problems they develop are browning and yellowing of needles and winter damage from snow and ice. Heavy snow weighs down flexible branches and the result is flopping and cracked stems that need to be tied and pruned come spring. As they get older, they become ragged-looking for these reasons. I have seen these trees butchered many times, from removing all lower branches to shearing too aggressively, which results in dead patches. Unlike some other trees and shrubs, if you remove too much of the foliage from an Arborvitae, it will be permanent and the branches in that area will die. It will not fill in with green growth or grow back from the older trunk wood or branches.
If you have an Arborvitae hedge, it’s wise to keep it lightly sheared and repaired annually to keep it healthy and tidy looking.
Deciding when to prune/trim is confusing to many people because there is no one-size-fits-all answer and even the experts can’t always agree. Yet, it is the most commonly asked question of gardeners, landscapers and arborists! Pruning of live branches is not as critical as many people think, but it is worthy of discussion.
The Best Times for Pruning: (the opposite of Part 1; Worst Times)
In general, the optimal times for ornamental tree and shrub trimming is early spring and summer and those should be the go-to times if you are unsure. Don’t let timing keep you from grabbing your pruners if a haircut is truly needed and you just can’t wait!
If you are trying to figure out the best time to prune/trim, start first with the worst times to prune (because more experts agree on these) and work backwards from there.
So, what are the worst case scenarios in pruning at the ‘wrong time’?
One important point is that pruning at the “wrong” time of year probably won’t kill your tree or shrub, but it may weaken it in the long run. Indeed many plants are trimmed at less than ideal times and yet they survive.
The Worst Times for Pruning:
To be continued in When To Trim, Part 2.
Well primarily because they are dead, they become dry and brittle and have a tendency to break off in strong winds. Especially the winds of our Nor’easters in the NorthEast. Also dead stubs and branches can be entryways for fungi and bacteria to enter live healthy wood at the attachment points and spread to other parts of the tree.This is especially a concern if the tree has an aggressive or infectious pest attacking it and/or trees nearby. Lastly, on some species, pruning out dead also will greatly enhance a tidy appearance of your trees, giving them a less ragged and messy appearance.
When weighing whether or not to spend the money to have them pruned out, some Q’s to ask yourself are;