Arborvitae that have been planted in hedge rows are often slender with only one or two leaders, the primary branches extending upward from the trunk. If an arborvitae begins to lean, follow these tips for assessing, correcting and saving it.
Step 1 - Determine Why It's Leaning
Arborvitae can lean for many reasons, including bending from winter snow weight, a leader that has veered off from the main trunk, or the top has bent from wind pressure from growing too close to a fence.
If it bore a heavy snow weight just in the past winter, disregard its lean. Arborvitae are known for their flexibility under snow and it will straighten up later in the spring by itself.
If the problem is a veering leader branch, try attaching the tree by cotton rope to a stake or other solid support. It may be early enough to alter the course of the leader's growth. Leave it staked for six to nine months, beginning in early spring, to see if it begins to grow more upward.
A tree's top bent by wind pressure may not be repairable, short of removing the fence. The top could be returned to a vertical position by tying it off, but as soon as you release the support, the wind will push it out of alignment again. Consult an arborist who has experience with arborvitae or other evergreens.
Step 2 - For How Long has it been Leaning?
If the arborvitae developed this lean as a sapling and it is now eight years old, it is not worthwhile trying to correct it. Live with its idiosyncrasy, or, if it is in danger of toppling, remove it.
If the arborvitae was very young when you purchased it and has just begun to lean at three feet in height, support it for the next nine to 12 months. Tie it to a tall metal stake with soft cotton rope to pull it upright.
If a young tree less than seven years old is leaning due to storm damage at less than 10 degrees and roots are still mostly in the soil, pull it upright with rope tied to two stakes on either side to exert balanced pressure on the trunk. Cover any exposed roots with mulch or soil to protect them.
A mature tree whose roots have been exposed and is leaning at more than 45 degrees must be taken down.
Step 3 - Replace Arborvitae That are Leaning Incorrigibly
Contact the garden center where you purchased the arborvitae if leaning becomes a problem in the first year. They can advise you on corrective measures or if it should be replaced.
If you are buying mature arborvitae as a privacy plant, inspect them from all angles for leaning. Do not purchase if they appear too crooked or tilted.
Buy arborvitae for hedge rows when young from a reputable garden products retailer. Watch them carefully as they mature to correct leaning when it first develops. Examine mature arborvitae closely before purchasing.