Chrysanthemums or mums are one of our favorite flowers in the fall. But to get big, bushy plants full of blooms, youll need to pinch or cut back the plant. This segment demonstrates two different methods to help the flower stems multiply.
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Mums are a quintessential fall flower, gracing porches and gardens with their vibrant bursts of color in autumn. However with proper care and pruning, mums can thrive as perennials returning with beautiful blooms year after year. Knowing when to cut back mums in the summer is key to keeping them healthy and promoting profuse flowering in the fall.
Why Cut Back Mums in Summer?
Cutting back mums during the summer serves several important purposes:
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It promotes bushy, compact growth rather than tall, leggy plants Mums that get too leggy are more likely to topple over under the weight of heavy flower blooms.
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Summer pruning encourages more blooms. More stems = more flowers.
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Cutting back controls the size and shape of the plant. Pruning mums in summer can help restrict their growth to fit smaller spaces in the garden.
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Deadheading spent blooms directs the plant’s energy into producing more flowers rather than forming seeds.
When to Start Cutting Back Mums
Timing is everything when it comes to pinching back mums. Follow these guidelines:
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Start pruning mums when they reach 6-8 inches tall in spring after new growth begins.
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Use sharp bypass pruners to snip off 1-2 inches from each stem, above a set of leaves. Make cuts at a 45 degree angle.
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Pinch or cut back mums every 2-4 weeks until mid summer. Never prune mums after July, as doing so may delay flowering in the fall.
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Remove spent blooms regularly through the summer to promote new bud formation. Deadheading is key for repeat flowering.
How Often to Prune Mums in Summer
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Plan to prune mums every 2-4 weeks from early summer until mid July.
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Pay close attention to how fast your mums are growing. If growth seems overly vigorous, pinch more frequently. If growth is slower, prune less often.
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Deadhead faded blooms at least once a week to encourage repeat flowering. Don’t let spent blooms linger.
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Discontinue pruning in mid to late July so flower buds can form for fall blooms.
Pinching vs Cutting Back Mums
There are two main pruning methods for mums – pinching and cutting back. Here’s how they compare:
Pinching
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Uses just your fingers to snap off tender new growth.
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Encourages bushier, more compact plants by removing stem tips.
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Causes less stress or damage than cutting.
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Best for light, routine pruning sessions.
Cutting
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Uses hand pruners or garden scissors to snip off larger chunks of growth.
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Helps significantly reduce plant size and shape mums.
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Useful for correcting leggy or overgrown plants.
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Cuts are slightly more damaging than pinching.
Pruning Potted vs Garden Mums
Proper pruning technique depends on whether you are growing mums in containers or in garden beds:
Potted Mums
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Use fingers to pinch main stems once every 2-3 weeks.
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Prune to shape the plant into a nice rounded ball.
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Remove any growth hanging over the edges of the pot.
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Stop pruning by mid July to allow buds to form.
Garden Mums
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Use bypass pruners to cut back long stems as needed.
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Prune into a mounded shape with an open center to allow air circulation.
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Cut back wayward stems growing beyond the main plant.
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Cease pruning by mid summer so flowers can develop.
Caring for Mums After Summer Pruning
After pruning mums in summer, provide care to keep them healthy:
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Water thoroughly after pruning to avoid stress. Mums prefer moist, well-drained soil.
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Apply an organic balanced fertilizer every 4-6 weeks to fuel growth.
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Monitor for pests like aphids or mites and treat any issues promptly.
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Add a 2-3 inch layer of mulch around mums to conserve moisture and suppress weeds.
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Stake tall mums in late summer to support the weight of heavy blooms.
When to Cut Back Mums After Blooming
After fall blooms fade, avoid cutting back mums right away. Here are tips for post-bloom care:
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Leave faded flower stems and foliage in place over winter to help insulate plant crowns.
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Trim back dead growth in early spring as new shoots emerge at the base.
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Apply fresh mulch around mums in spring to enrich the soil as they resume growth.
Properly cutting back mums at the right times encourages bushy, compact plants blanketed in colorful fall blooms. Pay close attention to your plants’ growth habits and prune diligently through summer. Then let those autumn flowers shine.
Transcript: How to Grow Big, Bushy Mums
Chrysanthemums or mums are one of our favorite flowers in the fall. But to get those big, gorgeous plants that bloom in September, October, and November, there’s a little bit of maintenance we need to do during the growing season. What we do is something called pinching back or cutting back. So, instead of one tall shoot, you’ll get a bunch of shoots that are shorter. If you let this shoot grow, it’s just going to continue to get taller and taller. And it will be real leggy by the time it blooms in the fall. But, by removing this top growth, it’s going to force all the side branches down into the axils of these leaves to develop. So, if I make the cut at this point, then it forces a shoot here, here…and here. So, I’m going to get about six different shoots coming up. They’re going to be shorter, and I’ll have a fistful of blooms this fall. We pinch or cut back chrysanthemums from the time they start to grow in the spring, and we make our last pinch or last cut around the fourth of July. We stop at that point in time, because then that gives the plant time to put on new growth, and set a flower bud that’s ready to bloom for the fall season. You can either go in there and individually snip back the shoots with a pair of scissors. This is a little bit time consuming and tedious. So, most gardeners may not want to do that. However, for the weekend warrior gardener, just get out there with your head shears to cut them back. It’s going to be a lot quicker, and it’s going to be a lot easier. And, it’s still going to allow all those new shoots to break and come up. Now, the trick to doing this with chrysanthemums is doing this several times. Whenever they put on about two to four inches of growth, then cut that back by about half. Now, you don’t want to cut down into where all those shoots will come back. So, our next cut is going to be a little bit higher, and our last cut is going to be even higher yet. Because, what we’re doing, is taking one stem, multiplying it, and multiplying it several times to get that bushy effect by the end of the season. This feature story prepared with Dennis Patton, Kansas State University Research and Extension Horticulture Agent, Johnson County. For more information, visit your local county extension office or visit our website at KansasGreenYards.org.
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How to Prune Fall Mums for a 2nd Bloom ✂️
FAQ
What happens if you don’t cut back mums?
This being said, you don’t have to pinch or prune mums at all. If you choose not to prune you might only get a short bloom period in summer, and it might be necessary to use plant supports to keep leggy stems from flopping over throughout the season.
How do you trim mums in the summer?
To encourage mums to bloom in the fall, trim them back in the summer, ideally from late June to July 4th. Pinching or pruning encourages a bushier plant with more blooms.
Are mums supposed to be cut back for winter?
For any mum in the garden, mulching can help it to survive the first winter as well as succeeding winters. Cut back the tops of plants after leaves have turned brown each fall. Use several inches of a loose, airy mulch that will allow light to get to the small side shoots throughout the winter.Nov 9, 2023
How to keep mums from getting too tall?
To prevent mums from becoming too tall and leggy, pinch back the stems regularly during the spring and early summer. This encourages bushier growth and more flowers, rather than a tall, sparse plant.