When Should You Prune Lavender Each Season?
If you aren't sure when to prune lavender this year, you aren't alone! Pruining can be tricky for many different plants, and lavender is no different. In this article, gardening expert and former organic lavender farmer Logan Hailey walks through the best times of the season to start pruning your lavender plants.
With its intoxicating fragrance and bee-alluring blooms, lavender is a joy to have in the garden. This perennial herb is remarkably hardy and easy to care for once it gets established. Lavender plants require very little water, no fertilizer, and can live for 5-10 years or more! The only maintenance this delightful herb requires is regular pruning– but when?
Pruning can be an intimidating process when you don’t know when or how to do it. You don’t want to cut back your plant too hard and hurt it, but you’ve also heard that un-pruned lavender can get pretty out of hand.
In reality, pruning is as simple as a twice-a-year haircut for your lavender plant. The process can even be a simple part of your flower harvesting routine! Let’s dig into everything you need to know about the best time of year to prune lavender.
The Short Answer
Lavender should get pruned twice per year, in the late spring and in the fall after it’s done blooming. Fading flowers are the easiest reminder that it’s time to prune your lavender. In fact, you can use your harvest days as a quick excuse to prune back the floral stems. The spring pruning encourages more summer blooms, while the fall pruning helps prepare your plant for winter and a vigorous season of growth next year.
The timing of these prunings perfectly correlates with the end of each flush of flowers. This is the perfect opportunity to grab your pruners and stimulate fresh, new growth. While it may seem like you’re cutting away the lavender’s flower stems, pruning twice per year actually promotes more flowering, healthier foliage, and a more aesthetic plant growth habit.
The Long Answer
A greater abundance of fragrant lavender blooms is undeniably the dream of any herb grower. If you want to maintain vigorous, aesthetically-pleasing lavender shrubs, then pruning is absolutely essential.
Un-pruned plants can look pretty mangled. When left to grow on their own, they often get very woody and out-of-hand, which makes them more susceptible to disease issues or even uprooting in high winds. This also means less of those coveted flowers you crave.
- A nice mounded shape.
- More flower production.
- Healthier foliage.
- Less disease risk.
- Less woody growth.
Remember that all lavender blooms from same-year growth. In other words, the stems that grow in the spring are the same ones that will produce flowers.
Soft Spring Pruning
Right after this perennial herb blooms in the spring, it’s time to “soft” prune. This spring pruning encourages a new flush of blooms and a healthy regeneration of the young foliage.
It is my favorite time to harvest stems for bouquets or drying while simultaneously giving my plants a nice haircut. By cutting down to a few inches above the soft green new growth, you are stimulating the plant to prepare for a perfumey summer show.
Just be sure you only cut the foliage back by one-third to one-half of its length. Never cut down into the woody part of the plant. Always use sharp, sanitized pruners.
How to Prune Lavender in the Spring:
- Wait until lavender flowers begin to dry and end their lifespan.
- Locate the woody central base of the plant,
- Go up 2-3” from the base to where the soft, green new growth begins.
- Prune off the upper shoots by at least one-third of their length.
- This ensures you are only cutting soft growth.
- Bundle and dry the flower stems or compost them.
- Cut the plant into an arc-shaped mound as you prune.
- For reblooming varieties, you can “deadhead” them in mid-summer.
- Don’t cut back as far as you did during spring pruning.
Hard Fall Pruning
The heavier fall prune is where you cut back about two-thirds of the plant’s growth and create the shape you want to promote in the next season.
The key goal of fall growth is to drive energy away from the plant’s above-ground growth and channel its efforts into the roots. Lavender needs a robust root system to help it through the winter.
This helps encourage better air circulation within the shrub to help prevent rotting issues. It also ensures that the plant can withstand snowpack or winter winds without breaking off the weak branches.
Again, you will want to wait until the last flush of blooms has started to fade before starting to prune. However, be sure that you do this before the danger of frost sets in.
Many professional lavender farmers prune about 5-6 weeks before the estimated first frost date for their region. This is often around September through October in zones 6 through 9.
Again, always use a disinfected sharpened knife or shears to prune. Dull, unsanitized tools can result in splitting or cracking the stems and introducing disease.
Pruning in the Fall
- First snip off any flower stems you haven’t harvested yet.
- This will reveal the shape oft he plant underneath.
- Locate the center woody crown.
- Draw an imaginary circle around the perimeter.
- Visualize where you’ll prune to create a mounded shape.
- Cut the green growth and stems about 1-2” above the woody center.
- Some branches will need more taken off than others.
- This will help maintain the shape and extend evenly from the center.
- Leave behind 1-3” of stems.
- Look at eye level and step back to get an idea of the shrub’s shape.
- Imagine a gumdrop or a mound.
- Prune any final diagonal bits to shape the plant for next year’s growth.
As you can tell, this process is really straightforward and doesn’t need to be scary or overcomplicated. As long as you avoid these common mistakes, you can confidently prune your lavender plants every season without worry.
Mistake #1: Cutting Into The Wood
The most important rule for pruning lavender is to avoid cutting into the woody portion of the plant. If you cut off too much of the woody base, it can severely damage or even kill your lavender plant.
However, you can make small exceptions for specific branches or sections that overgrew the rest. Think of this crown as the trunk of a tree: cutting off a few larger branches won’t hurt it, but chomping across the center can kill the tree.
Lavender plants are semi-woody perennials that straddle the line between a woody tree and an herbaceous shrub.
This means that we should stick to mostly pruning the herby, green, soft growth. But don’t be afraid to cut back small woody branches that may pose a risk to the plant (in high winds or snowpack, for example).
Mistake #2: Not Pruning Enough
In general, gardeners tend to prune their plants too lightly out of fear of hurting them. This actually allows the plants to grow too much each season, creating an unruly shape and fewer flowers. We should think of pruning as a pleasant haircut, not a pant punishment!
Farmers like Lavender Connection recommend pruning harder than you think you need to. In fact, they sometimes– gasp– break the “never cut woody parts” rule if certain branches have gotten out of hand. As long as you don’t cut back huge portions of the lavender’s wood, it should be just fine.
A great rule of thumb is: if you can’t easily prune the stem with hand pruners or scissors, it’s probably too woody and should be left alone.
Mistake #3: Pruning Too Late
If you forget to prune in early fall, it’s often best to wait until the next spring to return to your routine.
Remember that pruning encourages tender new growth. If you prune in late autumn just before the frosts begin, that new growth will be killed by the winter cold and weaken the plant.
Mistake #4: Not Pruning Young Plants
Many beginner lavender growers think that they should let their plants get established before they start pruning. In actuality, the first 3 years of a lavender’s lifecycle is the most important time to prune.
Heavily pruning during the establishment phase ensures that it can grow in a compact, shaped base that will help the plant stay healthy into its maturity.
Fall pruning is the most important for young plants because it reminds them not to put too much energy into showy new flowers when they should be building up a solid foundation in their root zone. What a great metaphor for coming of age!
Frequently Asked Questions
What time of year should lavender be pruned?
Lavender should ideally be pruned twice per year: once in the spring and once in the fall. The spring pruning happens afte the first flush of flowers has started to fade. The fall pruning should occur after summer flowers have started to fade, but at least 5 to 6 weeks before the expected first frost date.
Can I prune in May?
March through early May is a great time to prune in most climates. Wait until the plant’s first flush of flowers has started to fade, then grab your shears and get to pruning to encourage fresh, vibrant new growth and more summer blooms.
How far do you cut back lavender?
During spring pruning, lavender is typically cut back by about one-third to one-half of its length. In the fall, you can prune a little harder by cutting back up to two-thirds of the growth. Be sure to leave at least 1-3” of green foliage above the woody portion of the plant.
What happens if you don’t cut lavender?
Cutting lavender allows you to enjoy a flower harvest and encourage more blooms. While many gardeners fear or dread pruning, it’s actually incredibly important for the shape, health, and vigor of the plant.
If you don’t prune, it can become very unruly and more prone to disease. It also can be susceptible to breakage or damage in winter storms. Lastly, un-pruned plants often look bad in the garden because it doesn’t have that classic mounded, tidy shape you see at lavender farms.
Lavender pruning doesn’t have to be a daunting task. In fact, it can become a super quick and easy routine that you get excited about every spring and fall. Once lavender finishes its flush of flowers, prune back about one-third of the stems in the spring, leaving 2-3” of green growth.
After the second round of blooms in the fall, prune again, this time cutting back a bit harder and shaping the plant. You can go down to just an inch above the woody parts if necessary.
When in Doubt, Remember:
- The first 3 years of growth are most important for pruning.
- If you avoid pruning, you’ll encounter blooming problems and disease.
- Most gardeners prune too lightly.
- Don’t be afraid to give your lavender a big haircut.
Lastly, don’t let those lavender prunings go to waste! You can get even more bang for your buck by utilizing pruning branches as cuttings.