When To Prune Lavender In Colorado

When to prune lavender in Colorado really comes down to timing, and that timing is more specific than in many other states.
 
You should prune lavender in Colorado twice a year, with the main, hard pruning happening in early spring and a lighter trim in late summer.
 
This unique schedule helps your lavender survive Colorado’s intense sun, drastic temperature swings, and heavy snow, all while encouraging healthy, bushy growth.
 
If you’ve ever wondered when to prune lavender in Colorado, or if you’ve been hesitant to cut back your plants because you’re afraid of killing them, this guide is for you.
 
We’ll cover the exact months, the right techniques, and the common mistakes to avoid so you get the timing just right.
 
Let’s jump right in and make sure your lavender thrives.
 

When To Prune Lavender In Colorado: The Early Spring Window

The absolute best time for the main prune when you prune lavender in Colorado is in early spring, typically from mid-March to early April.
 
This is the window where the worst of winter’s deep freezes are behind you, but the lavender is still dormant or just waking up.
 
Pruning at this time removes any winter-damaged, dead, or woody growth and gives the plant a fresh start for the growing season.
 
If you wait until the new green growth has significantly taken off, you risk cutting off that tender new growth and stunting the plant.
 
So, when you ask when to prune lavender in Colorado, early spring is your most critical answer.
 

1. Why Early Spring Pruning Is Non-Negotiable

Lavender in Colorado faces harsh conditions, including drying winds and freezing temperatures that kill off the upper stems.
 
By pruning in early spring, you’re clearing away all that dead material that can harbor moisture and cause rot as the weather warms.
 
It also stimulates the plant to push out fresh, vigorous shoots from the base, which is exactly what you want.
 
This is the time to cut back the plant significantly, usually by about one-third to one-half of its total height.
 
You’ll want to cut into the green, living wood, but never cut into the old, brown, leafless wood at the very base.
 
That old wood doesn’t regrow, so if you cut too deep, you’ll be left with a bare, woody skeleton.
 
A good rule of thumb is to leave a few sets of new green leaves on every stem after you prune.
 

2. Watch For The “Green” Sign

Before you start your early spring prune, check your lavender for signs of life at the base.
 
Gently scratch a stem with your fingernail right where the new leaves are emerging.
 
If you see green underneath, you’re in the clear to prune.
 
If you still see brown and brittle, give it a week or two and check again because the new growth may not have started yet.
 
The key when to prune lavender in Colorado is to always wait until you see new green shoots at the base of the plant before you make your cuts.
 
This confirms the plant is alive and ready to push out new growth after your pruning.
 
Pruning too early in a particularly cold spell can expose fresh tissue to a hard freeze, which will set the plant back.
 

When To Prune Lavender In Colorado: The Late Summer Trim

The second time you’ll prune lavender in Colorado is in late summer, right after the first flush of flowers has faded, usually in August.
 
This isn’t a hard prune like in spring; it’s more of a light shaping and deadheading session.
 
The goal here is to remove the spent flower stalks and trim about a third of the new growth to keep the plant compact and encourage a possible second, smaller bloom.
 
This late summer trim also helps reduce the woody base from developing too rapidly, which keeps your lavender looking lush and full.
 

3. How To Do The Late Summer Trim

For this prune, you’ll simply take a pair of sharp shears and cut back the flowering stems to just above a set of leaves.
 
Don’t cut into the old wood, just shape the green growth into a nice, rounded mound.
 
This is a good time to remove any lanky or leggy stems that are ruining the plant’s shape.
 
This trim is about tidying up and promoting airflow, which is crucial to prevent fungal issues in Colorado’s monsoon season.
 
You want to do this by mid-September at the latest.
 
If you wait too long into the fall, the new growth stimulated by pruning won’t have time to harden off before the first frosts arrive.
 
That tender new growth would then be killed, causing unnecessary winter die-back.
 

Avoiding The Biggest Pruning Mistakes

Now that you know when to prune lavender in Colorado, it’s just as vital to know what not to do.
 
Many gardeners are nervous about pruning, so they only trim the very tops of the flowers, leaving the plant to get woody and floppy.
 
Others make an even bigger mistake by cutting into the dead, woody base, which will not regenerate.
 

4. Never Cut Into Old Wood

This is the golden rule of lavender pruning.
 
When you prune lavender in Colorado, remember that the woody stems at the bottom of the plant have no dormant buds.
 
Once you cut into that brown, bark-covered wood, the stem will not grow back.
 
If you cut all the stems down to that old wood, you’ll kill the plant.
 
Always leave a couple of inches of green, leafy growth on the stem.
 
This ensures the plant can still photosynthesize and push out new stems from those green nodes.
 

5. Don’t Prune In Late Fall

You might think you should cut it back for winter, but you should not prune lavender in late fall.
 
Pruning stimulates new growth, and if you do it in October or November, that growth is tender.
 
A sudden cold snap will kill it, and that dead growth can then spread disease or rot down into the healthy parts of the plant.
 
The dead flower heads and stems we leave on in winter actually provide a layer of insulation against the freezing winds.
 
So, leave your lavender completely alone from October until the following March.
 
This patience is exactly what the plant needs to survive its first winter in Colorado.
 

So, When To Prune Lavender In Colorado?

When to prune lavender in Colorado is clear: you prune in early spring and again in late summer.
 
You prune in early spring to remove winter damage and shape the plant, and you prune in late summer to tidy up and encourage a second bloom.
 
You avoid pruning in the fall entirely so you don’t risk new growth dying in the first frost.
 
If you stick to this schedule, your lavender will stay healthy, compact, and productive for many years.
 
So, the answer to when to prune lavender in Colorado is to prune in early spring and again in late summer, and always avoid the fall.
 
Get out there, make those clean cuts, and enjoy the beautiful fragrance and resilient beauty of your lavender all season long.