Pruning
Summer is the perfect time to refresh your mums—cutting back now prevents leggy stems and ensures next year’s blooms will be bold and abundant. I’ve spent years pruning these tough perennials, and the difference between a thriving plant and one that fades is all in the timing and technique.
Most gardeners wait until fall, but summer pruning actually strengthens growth and improves winter hardiness.
The key is to cut back one-third of the plant’s height right after the first flush of blooms fades, using clean, sharp pruners. Avoid hacking at the stems—aim for just above a leaf node or bud to encourage new growth.
This isn’t about shaping; it’s about redirecting energy so your mums store up strength for next season. (Yes, I’ve killed plants with overzealous pruning—learned that the hard way.)
After pruning, your mums will bounce back with fresh, bushier foliage in 3-4 weeks, setting the stage for a stronger root system. The result? More vibrant blooms next year and plants that shrug off winter’s chill.
Just be sure to water deeply afterward and avoid fertilizing right away—let those new shoots establish first.
This method works for all mums, whether you’re growing them in garden beds, containers, or even as fall border stars. The only exception? If you live in a hot, dry climate, wait until late summer to prune—heat stress can slow recovery.
Now grab those shears and give your mums a second chance to shine.
📚 In This Guide
- What you need
- Instructions
- Tips and common mistakes
- Wrapping up and next steps
What you need
- ● Pruning shears or bypass pruners – Choose sharp, sterilized shears (preferably with a 4- to 6-inch blade) to avoid crushing stems or spreading disease. 🔪
- ● Gloves – A pair of gardening gloves (nitrile-coated for grip or leather for durability) to protect your hands from thorns and dirt.
- ● Disinfectant (70% isopropyl alcohol or bleach solution) – Clean your tools before and after pruning to prevent bacterial/fungal spread. Mix 1 part bleach to 9 parts water for a DIY sanitizer.
- ○ Garden twine or plant ties (optional but helpful) – Useful for tying back leggy stems if you’re shaping for next year.
- ● Trash bag or bucket – For collecting pruned stems and debris. A 5-gallon bucket works well for larger jobs.
- ● Watering can or hose with a gentle spray nozzle – Keep your mums hydrated before and after pruning to reduce stress.
- ● Hand pruners (for smaller stems) – Great for detailed trimming in tight spaces.
- ● Loppers (for thicker stems) – If your mums have ½-inch+ stems, loppers make the job easier.
- ● Compost bin or mulch – Repurpose pruned stems as green material for compost.
- ● Plant food or fertilizer – A balanced 10-10-10 or bloom-specific fertilizer to give your mums a post-prune boost.
- ● Safety glasses – Protect your eyes if you’re dealing with overgrown, thorny mums.
Step-by-step instructions for cutting back mums in summer
Revitalizing your mums mid-season keeps them healthy and ensures next year’s showstopping blooms.
✂️ Step 1: Wait for the Right Time to Prune
Never cut back mums after they’ve bloomed for the season—you’ll sacrifice next year’s flowers. Instead, prune in early to mid-summer, specifically between June and early July, when the plants are actively growing but haven’t yet set buds for fall blooms. Look for stems that have finished flowering and are starting to look leggy or crowded. These are the ones to trim first.
If your mums are still in full bloom, wait until at least 2-3 weeks after the last flowers fade. Cutting too early removes potential blooms for the current season. The goal is to shape the plant while leaving enough energy for new growth and future flowers.
✂️ Step 2: Use Clean, Sharp Pruners and Sanitize Tools
Grab your clean, sharp pruners—dull blades crush stems and invite disease. Before you start, wipe the blades with rubbing alcohol or a 10% bleach solution to prevent spreading bacteria or fungus between cuts. I like to sanitize my tools after every 3-4 plants to keep everything sterile.
Make cuts at a 45-degree angle, about ¼ inch above a leaf node or a healthy side branch. Avoid cutting into old, woody stems—they won’t regenerate well. Focus on removing dead, damaged, or overcrowded stems first. This opens up the center of the plant for better airflow and sunlight penetration.
✂️ Step 3: Thin Out Overcrowded Stems for Better Airflow
Mums grow bushy, but too many stems compete for nutrients. Aim to leave 3-5 of the strongest, healthiest stems per plant. Remove any stems that are weak, crossing, or growing inward—these create shade and trap moisture, which leads to fungal issues like powdery mildew. The more open the plant, the better it can recover and grow new shoots.
If you’re unsure which stems to keep, look for ones with dark green leaves and thick, sturdy growth. Thin from the base if needed, but never leave stubs longer than 1-2 inches—they won’t sprout new growth. After pruning, step back and check for balance. The plant should look full but not crowded.
💧 Step 4: Water and Fertilize After Pruning
Give your mums a deep watering right after pruning to help them recover. Water at the base of the plant, avoiding the foliage to prevent fungal diseases. Let the top 1-2 inches of soil dry out between waterings to avoid soggy roots. Overwatering after pruning can stress the plant further, so monitor the soil closely.
Feed with a balanced, slow-release fertilizer (like a 10-10-10) to support new growth. I sprinkle a small handful around the base and water it in. Avoid high-nitrogen fertilizers—they encourage leafy growth at the expense of flowers. Instead, choose a formula with equal parts nitrogen, phosphorus, and potassium to promote both foliage and root health.
☀️ Step 5: Monitor for New Growth and Adjust Care
Within 2-3 weeks, you should see new shoots emerging from the base or along the remaining stems. This is your sign the plant is recovering well. Keep the area weed-free and mulch lightly with 2-3 inches of shredded bark or straw to retain moisture and regulate soil temperature.
If new growth is slow or sparse, check for pests like spider mites or diseases like powdery mildew. Treat early with neem oil or insecticidal soap if needed. By late summer, your mums should be bushier and healthier, setting the stage for vibrant fall blooms. With proper care, they’ll reward you with even more flowers next year!
Tips & tricks for perfect summer mum pruning
These simple strategies will help you revitalize your mums without sacrificing next year's blooms.
Timing is Everything: The window between June and early July is critical for summer pruning. I’ve learned this the hard way—pruning too late can leave your mums vulnerable to fall frost before they’ve had time to recover. Look for the "leggy" stems that have already finished flowering; these are your first targets. The goal is to shape the plant while preserving its energy for new growth, not to remove all the flowers at once.
Tool Prep Makes All the Difference: Sanitizing your pruners between cuts is non-negotiable. I keep a small spray bottle of rubbing alcohol handy and wipe down the blades after every 3-4 cuts. This simple step prevents the spread of bacterial and fungal diseases that can turn your pruning session into a disaster. Also, always make cuts at a 45-degree angle—this increases the surface area for faster healing and reduces the risk of water pooling at the cut site.
Thinning Strategy for Healthier Plants: When you’re thinning those crowded stems, aim to leave 3-5 of the strongest, healthiest ones per plant. I like to visualize the plant from above—imagine you’re looking at a clock face. The stems you keep should be evenly spaced like numbers on a clock, with plenty of room between them. This creates the perfect airflow and sunlight conditions for recovery. Remember, you’re not just pruning for looks; you’re creating an environment where your mums can thrive.
Post-Pruning Care is Just as Important: That deep watering right after pruning isn’t just a suggestion—it’s essential. The plant needs to replenish moisture lost during the cutting process. I also recommend applying a light layer of mulch (about 2-3 inches) after watering. This helps regulate soil temperature and retain moisture, which is especially important during hot summer months. The mulch also acts as a barrier against weeds, reducing competition for nutrients.
Pro Tips for Cut Back Mums In The Summer
- These simple strategies will help you revitalize your mums without sacrificing next year's blooms.
- Timing is Everything: The window between June and early July is critical for summer pruning.
- Tool Prep Makes All the Difference: Sanitizing your pruners between cuts is non-negotiable.
Frequently asked questions
Got questions about cutting back mums in summer? You’re not alone! Here are some of the most common concerns—and their answers—to help you prune with confidence.
When is the exact best time to cut back mums in summer?
The ideal window is late summer, after blooming but before fall frost—typically mid-to-late August in most climates. This gives plants time to recover before winter dormancy. If you miss this, a light trim in early September still works, but avoid heavy cuts too close to cold weather.
How much should I cut back? Should I cut to the ground?
Never cut all the way to the ground! Aim to trim back 1/3 of the plant’s height, leaving about 6–8 inches of stems. This encourages bushier growth and prevents disease. Think of it like a haircut—shape and refresh, not a buzz cut!
What if it’s super hot when I prune? Will that hurt my mums?
Pruning in extreme heat (above 90°F) can stress plants, but it’s not a dealbreaker. Water deeply 2–3 days before and after to help recovery. Early morning or late afternoon pruning minimizes heat shock. If temps are scorching, wait until late summer when days cool slightly.
Can I still get flowers next year if I cut back now?
Cutting back in summer revitalizes mums for next year’s blooms by removing spent growth and redirecting energy. Just avoid over-pruning—stick to the 1/3 rule. With proper care (fertilizer, water, and mulch), you’ll see even bigger, healthier blooms in spring!
What if my mums look sad after pruning? How do I fix it?
Don’t panic! Yellow leaves or wilting are normal for a few weeks as the plant adjusts. Boost care with:
- Weekly watering (1 inch per week)
- Balanced fertilizer (10-10-10) after 4–6 weeks
- Mulch around the base to retain moisture
Wrapping up and next steps
Cutting back mums in summer isn’t just about tidying up—it’s your secret to bigger, brighter blooms next year! By following these steps, you’ll encourage healthier stems, prevent disease, and give your plants the energy they need to thrive. You’ve got this! 🌿✨
Now that you’re armed with the know-how, grab those pruners and get to work. Next up: Keep an eye on your mums in late summer—watch for new growth and adjust your care routine to prep for fall planting. Happy gardening!