Coreopsis (Coreopsis spp. is a well-known flowering plant whose happy, bright flowers attract bees, butterflies, and other good pollinators. These wildflowers are native to North America and are often called tickseed. They come in many species and grown types. Overall, coreopsis is low-maintenance, but pruning at the right time is important to keep plants healthy and flowering their best.
In this comprehensive guide, we’ll explore when and how to cut back coreopsis for optimal growth, bloom, and appeal
Why Deadhead and Prune Coreopsis
Deadheading and pruning coreopsis accomplishes several important things
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Removes spent blooms to encourage new flower production. Coreopsis flowers best on new growth.
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Prevents rampant self-seeding. Coreopsis left unpruned will spread seeds prolifically.
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Maintains a compact, shapely form. Pruning discourages leggy, unruly growth.
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Removes damaged stems and foliage.
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Promotes fall blooms on some varieties like threadleaf.
Proper pruning keeps coreopsis bushy and covered in flowers. It prevents tall, sparse growth and unwanted spreading. Well-timed cuts maximize blooms and aesthetics.
When to Prune Coreopsis
Timing is everything when it comes to pruning coreopsis. Here are the optimal times to trim plants:
Summer
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Deadhead spent blooms anytime to encourage rebloom.
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Cut back by 1/3 to 1/2 in mid to late summer to shape and compact growth. This also promotes fall blooms on some types.
Fall
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Cut perennial varieties back to within 6 inches of the ground after first frost.
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Leave annual coreopsis unpruned to allow self-seeding.
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Apply winter mulch around crowns in cold climates.
Spring
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Remove any remaining dead growth in early spring before new growth emerges.
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Resume fertilizing and watering.
How to Prune Coreopsis Step-by-Step
Follow these simple steps for pruning coreopsis successfully:
Summer
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Using clean, sharp pruners, remove spent blooms back to a leaf node or bud.
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In mid to late summer, cut plants back by 1/3 to 1/2 their height. Make cuts just above healthy buds or leaves.
Fall
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Cut perennials back to within 6 inches of the soil after the first frost, leaving 3 to 6 inches of stem.
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Clear away debris from base of plants. Mulch if needed for winter protection.
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Leave annual types unpruned to allow self-seeding.
Spring
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Remove mulch once all chance of frost has passed.
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Apply fertilizer or compost. Resume regular watering schedule.
Tips for Popular Coreopsis Varieties
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Threadleaf coreopsis: Shear in summer to shape dense 3 ft. plants. Cut back after frost for zones 3-9.
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Large-flowered coreopsis: Deadhead to extend blooms. Shear by 1/2 in summer. Cut back after frost in zones 3-8.
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Early Sunrise coreopsis: Shear by 1/2 in summer. Cut back after frost. Zones 3-9 perennial.
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Plains coreopsis: Deadhead summer blooms. No fall cut needed for zones 3-9 native.
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Calliopsis: Deadhead summer blooms. No fall cut for zone 6-10 annual.
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Lance-leaved coreopsis: Prune spent blooms. Cut back after frost. Zones 4-9 perennial.
When Not to Prune Coreopsis
Avoid pruning coreopsis at the wrong times, which can damage plants:
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In early spring before new growth resumes
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In peak summer during main bloom time
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Too severely in fall, leaving less than 3-6 inches of stem
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In winter during dormancy
Frequently Asked Questions About Cutting Back Coreopsis
Should I cut coreopsis back for winter?
For perennial types, yes. For winter protection, cut back to 6 inches after first frost, leaving 3-6 inches of stem. Annuals can be left for self-seeding.
When do I prune coreopsis after flowering?
Cut off spent flowers as soon as they fade by deadheading to a leaf node. To shape plants, cut them back by 1/3 to 1/2 in the middle to end of summer.
Do I cut coreopsis to the ground in fall?
No, avoid cutting completely to the ground. Leave 3-6 inches of stem to protect the crown before cold weather arrives.
Can I cut back coreopsis too early?
Yes, avoid heavy pruning before new spring growth emerges or during peak summer bloom time. This can damage the plant.
Conclusion
Properly timing pruning is crucial for keeping coreopsis healthy and flowering its best. Deadhead spent blooms all season long. For shaping and compacting, cut established plants back by 1/3 to 1/2 in mid to late summer. In fall, cut perennial types back to within 6 inches of the ground after the first frost. Avoid pruning too early in spring or during peak summer blooms. With the right technique and timing, you can enjoy vibrant coreopsis flowers in your garden year after year.
Should I Cut Back Coreopsis in the Fall?
In the case of many perennials, cutting them back for the winter months helps them come back with vigor the following spring.
But for this short-lived perennial, cutting them back at all can sometimes be a death knell. The plant does better when the stems and leaves are left alone because they act as insulation and help keep the crown warm.
So no matter your growing zone, ideally you should leave the stems and foliage in place after the plant dies all the way back. The foliage turns a pleasing mahogany in the fall before it dries to a brownish-gray color, adding texture to your landscape.
Yes, you’re leaving yourself some work for the springtime. Once the ground is no longer frozen and there is no longer any risk of frost, all you have to do is cut the dead stems off about two to three inches above the ground. New flowers will then grow.
If you must have a neat, clean look in your garden throughout the winter, you can cut your coreopsis down to four to six inches above the ground. The stems will provide a bit of insulation for the crown and your landscape will look tidy. Don’t cut any more than this, or you risk losing your daisy-like perennial to winter’s harsh weather.
Avoid Compost and Fertilizer
For many plants, adding a layer of compost to the growing area in the fall can help get the soil ready for a healthy spring.
This is not the case with coreopsis. This plant actually thrives in average soil that’s not nutrient- or organically-rich. All it requires is for the soil to be well-draining. Nutrient-rich soil can encourage leggy growth.
It doesn’t require fertilization, either. If you do wish to fertilize, do so in the springtime. You don’t want to encourage new growth late in the season that will be killed by the first frost.