Wednesday, September 23, 2020

How to Prune Lavender for Winter

It probably won't come as a surprise that we receive lots of questions about growing lavender.  One of the most common questions is about pruning — how, when, etc.  Pruning is absolutely essential for good flower development and to prevent overly woody stalks.  It's an easy step in caring for your lavender plant, let's get to it.

We find the best time to prune lavender in the Pacific Northwest is fall, well before the first frosts come.  In your own garden, as you are preparing your other plantings for the winter, add "prune the lavender" to your fall gardening checklist.

We use gas-powered hedge trimmers to prune the 30,000+ plants in our fields.  Garden clippers or hedge shears (pictured) or even scissors work great for a few plants in the garden.


How far back to prune is now the important question.  Cut the flowers and stalks down to within 2 leaf nodes above the grey/brown woody part of the stem at the very base of the plant (leaving approximately 2-3 inches of green stalk).  To determine where this is on your plant, hold back some stalks so that you can see into the woody base of the plant.  Count 2 leaf nodes or 2-3 inches above the woody transition.  This is your pruning marker.

A good rule for your "green" thumb is — brown is bad, green is good.  You want to avoid cutting into the woody base of the plant.  Lavender does not tolerate pruning like many rose varieties that you can prune right down to the base of the plant.  Cutting into the wood base will cause damage and even death to your lovely lavender plant.  So remember, keep your pruning in the green stalks.  Brown is bad, green is good!

If your lavender plant has been deprived of its annual pruning for some years, it's likely become quite leggy and the woody base has begun to sprawl and will be quite top heavy when in bloom.  Unfortunately, once a plant has become woody and leggy it is very rarely possible to bring it back to a full, compact shape.  We suggest replacing the plant at this stage and starting your pruning rhythm at year one.  That's what we do at the farm.

Back to pruning... Once you have established your pruning marker, grab your tool and get at it.  As you do so, try to maintain a compact hemispherical shape.  This will help maintain the shape of the lavender plant the following season. When you are finished the lavender plant should look like a little grey/green hedgehog.

 

Once pruned the plants enter their winter dormancy until the new growth appears in the spring.  After you have pruned all your plants, you'll likely have quite a collection of clippings.  These clippings make a wonderful mulch or, at the very least, addition to the compost bin.  

With these pruning tips at the ready, mark "prune the lavender" on your calendar this fall well before the first frosts arrive.  You'll thank yourself in the spring with the new growth comes bursting forth, energized from a long winter's nap.  Enjoy "tucking your lavender in" for the winter.  

If you have any questions, we're always here for you and your lavender.

8 comments:

  1. If the plant is potted and brought indoors does it still need pruning?

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    1. Yes, all lavender (potted or otherwise) needs to be pruned each year.
      Lavender prefers to be outside, but it does not like long, hard freezes. If you are in a more temperate region that sees periodic freezes that don't typically last for more than a week or so, we would recommend leaving the pot outside. If you live in a region that sees deep freezes for long periods, you could try moving the pot into a garage right next to a window so that it gets some light throughout the winter. This latter method may have variable results, however. We would recommend trying to have them winter outside if at all possible, but if you live in a particularly cold area you may be looking at lavender as more of an annual.

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  2. At the beginning of the season I bought 2 small lavender plants and put them in one large clay pot, about 24 inches in diameter. They grew beautifully over the summer. Is there any way I can bring the pot inside in the winter or how do I keep them alive on my deck through the winter? Help, this is the first year I did well with lavender. Or do I just say goodbye and start over in the spring?

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    1. We're delighted that your lavender is doing well! As for wintering in a pot, it really depends on where you live. Lavender prefers to be outside, but it does not like long, hard freezes. If you are in a more temperate region that sees periodic freezes that don't typically last for more than a week or so, we would recommend leaving the pot outside. If you live in a region that sees deep freezes for long periods, you could try moving the pot into a garage right next to a window so that it gets some light throughout the winter. This latter method may have variable results, however. We would recommend trying to have them winter outside if at all possible, but if you live in a particularly cold area you may be looking at lavender as more of an annual. Really, it all depends on where you live.

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  3. Thank you very much for this information... I just retired and I finally have time to tend to the lavender. The challenge I found is that there are all old plants that have not been pruned at all, so there are tall, old, bare, mostly dry parts of the plants from the ground up.
    I think they may need to be just replaced, like I read in this article. My dilemma is about when to plant the new lavender plants; now (since here in Arizona is still "late summer"), or in the Spring?
    Please help! Thank you...

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    1. Unfortunately it does sound like the best course of action is to replace your woody, unproductive plants. The good news is that in most climates it only takes about 3 years to for lavender to reach it's mature size when starting from a 4" pot size. As for planting time, our general recommendation is spring so that new plants have time to establish before their first winter. Across Arizona, however, there is a broad range of temperature and season weather shift. Your particular micro-climate might call for something different. We would recommend connecting with a local nursery and getting their input about your specific region.

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  4. Thank You for the helpful information.

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    1. You are very welcome. We love sharing all things lavender!

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