Your Cool Home is supported by its readers. Please assume all links are affiliate links. If you purchase something from one of our links, we make a small commission from Amazon. Thank you!
The best time to prune arborvitaes is in late winter or early spring, just before new growth begins.
This timing is ideal because the shrub is still dormant, which means less stress on the plant.
If you’ve been wondering when is the best time to prune arborvitaes, the answer really comes down to this narrow window before the growing season kicks in.
Pruning arborvitaes at this time gives them a full season to recover and put out healthy new foliage.
In this post, we’ll explore why this timing works best, how to approach pruning arborvitaes safely, and what to avoid so your trees stay lush and green.
Let’s dig into the details.
Why Late Winter Is The Best Time To Prune Arborvitaes
Pruning arborvitaes in late winter or early spring is your safest bet for a few solid reasons.
1. Dormancy Means Less Sap Loss
When you prune arborvitaes during dormancy, the plant isn’t actively pushing sap through its branches.
This reduces the risk of excessive sap bleeding, which can weaken the shrub.
Dormant pruning also means the cuts heal faster once growth resumes in spring.
So if you’re asking when is the best time to prune arborvitaes, dormant season wins every time.
2. You Avoid Damaging New Growth
Pruning arborvitaes in late winter means you’re cutting before any tender new shoots emerge.
If you wait until mid-spring or summer, you risk snipping off fresh growth that took weeks to develop.
That new growth is what gives arborvitaes their full, dense appearance.
By pruning arborvitaes early, you ensure the shrub can channel all its energy into producing strong, healthy foliage rather than repairing damaged tips.
3. Less Stress From Pests And Diseases
Late winter is typically a low-pressure time for pests and fungal diseases.
Pruning arborvitaes in summer can expose fresh cuts to insects that are actively searching for feeding sites.
But when you prune arborvitaes in late winter, those open wounds seal quickly in the dry, cool air.
This dramatically lowers the chances of infection or infestation taking hold.
4. Shape Is Easier To See
Without dense foliage blocking your view, you can actually see the structure of the branches.
This makes it so much easier to identify dead, damaged, or crossing limbs.
Pruning arborvitaes when the branches are bare lets you make precise cuts that improve airflow and light penetration.
Plus, you’ll avoid the frustration of guessing where to cut through a thick wall of green needles.
Can You Prune Arborvitaes In Other Seasons?
While late winter is the best time to prune arborvitaes, life happens and sometimes you need to trim at other times.
Let’s look at how other seasons stack up.
Pruning Arborvitaes In Summer
Summer pruning is possible but should be very light.
Pruning arborvitaes in summer, especially during heatwaves, can stress the plant because it’s already working hard to stay hydrated.
If you must prune arborvitaes in summer, only remove small amounts of growth and never cut back into bare wood.
Arborvitaes won’t regrow from old wood, so this is a critical rule no matter the season.
Pruning Arborvitaes In Fall
Fall is the worst time to prune arborvitaes.
Pruning arborvitaes in fall encourages new growth that won’t have time to harden off before frost hits.
That tender growth will die back in winter, leaving you with brown, ugly tips.
So even though you might be tempted to tidy up before winter, resist the urge and wait for late winter instead.
Pruning Arborvitaes In Early Spring
Early spring, right as the ground thaws, is almost as good as late winter.
Pruning arborvitaes in early spring still catches the plant before major growth begins.
Just be careful not to wait too long—once you see new buds swelling, hold off.
The key is that the best time to prune arborvitaes is always before that flush of fresh green appears.
How To Prune Arborvitaes Correctly
Knowing when is the best time to prune arborvitaes is only half the battle.
You also need to prune them the right way so they stay healthy.
1. Never Cut Into Bare Wood
This is the golden rule of pruning arborvitaes.
Arborvitaes don’t have dormant buds on old wood, meaning if you cut back to brown, leafless branches, those branches will never grow back.
When pruning arborvitaes, always leave some green foliage on each branch you trim.
This ensures the shrub can keep photosynthesizing and producing new growth.
2. Use Sharp, Clean Tools
Dull blades crush the wood, creating jagged cuts that heal slowly.
Before you prune arborvitaes, sharpen your shears and wipe them down with rubbing alcohol.
Clean tools prevent spreading disease between plants.
And for thicker branches, use loppers or a hand saw for a clean, smooth cut.
3. Trim Lightly, Not Hard
Pruning arborvitaes should be about shaping, not heavy reduction.
Only remove about one-third of the green growth at most in a single year.
If you need to reduce the height or width significantly, do it gradually over several seasons.
Aggressive pruning arborvitaes all at once can shock the plant and lead to dieback.
4. Cut At A Slight Angle
When you prune arborvitaes, make your cuts just above a healthy bud or side branch.
Angle the cut slightly so water runs off the surface rather than pooling.
This simple step helps prevent rot and keeps your cuts healing quickly.
Signs That Your Arborvitae Needs Pruning
Even if you know the best time to prune arborvitaes, you still need to recognize when they actually require it.
1. Dead Or Brown Branches
If you notice dry, brittle branches that snap easily, it’s time to prune arborvitaes.
These dead limbs not only look bad but can also attract pests.
Remove them at the base, but again, only if there’s green growth nearby to support the cut.
2. Overgrown Or Uneven Shape
When your arborvitae starts looking lopsided or is encroaching on a walkway, pruning arborvitaes becomes necessary.
Light shaping in late winter will keep them neat and tidy without harming the plant.
3. Dense Interior That Blocks Light
If the inner branches are so thick that sunlight can’t reach them, those inner needles will turn brown and drop.
Pruning arborvitaes to open up the center improves airflow and keeps the interior foliage alive.
This is a great reason to prune arborvitaes even if the outside looks fine.
So, When Is The Best Time To Prune Arborvitaes?
The best time to prune arborvitaes is late winter to early spring.
Pruning arborvitaes during dormancy minimizes stress, prevents disease, and sets the stage for vigorous new growth.
Avoid fall pruning at all costs, and keep summer cuts extremely light.
Remember to always leave green foliage on the branches and never cut into bare wood.
With this timing and technique, your arborvitaes will stay lush, dense, and beautiful all year long.
So mark your calendar for late winter, grab your sharp shears, and give your arborvitaes the care they deserve.
Happy pruning!