When to Cut Back Chrysanthemums for Maximum Fall Blooms

Chrysanthemums, also known as mums, are iconic fall-blooming perennials loved for their burst of colorful flowers. Getting the most out of your mums each season depends on proper pruning. Knowing when to cut back chrysanthemums is key to having lush, full plants that put on a vibrant floral display.

With the right pruning schedule, you can keep your mums under control while coaxing a flush of flowers. Follow this complete guide to learn when and how to prune chrysanthemums for amazing autumn blossoms year after year.

Why Pruning is Key for Chrysanthemums

Chrysanthemums are fast-growing perennials that can get quite unruly if left alone Pruning accomplishes several important things

• Shaping Cutting back overgrown stems maintains a compact rounded habit.

• Flower induction Pruning encourages more blooms by redirecting energy into flower bud production.

• Rejuvenation: Removing old stems reinvigorates the plant so it stays vigorous.

• Height control: Cutting tall stems back prevents flopping under the weight of flowers.

In addition to the when, proper technique is equally important for pruning mums successfully.

How to Trim Chrysanthemums Step-By-Step

Follow these tips for trimming your mums correctly:

Spring Pruning

• Wait until new growth appears in spring, then trim stems back by 1/3 to 1/2 their height. This removes dead winter growth.

• Make cuts just above strong, outward facing buds or leaves. Never leave bare stubs.

• Remove any diseased or damaged stems entirely.

Summer Pinching

• When stems reach 4-6 inches in spring, pinch off 1-2 inches from the tip using your fingers.

• Repeat every 2-3 weeks until midsummer. Pinching forces branching and keeps plants full.

Fall Shaping

• If plants get leggy or floppy later in summer, cut back by 1/3 to reshape.

• Stop pruning 6-8 weeks before your desired bloom time to allow flower buds to set.

• Stake tall varieties that need extra support using soft plant ties.

Proper technique is key for getting the most out of your pruning. Always use clean, sharp pruners and make cuts just above leaf nodes or buds. Remove spent blooms promptly after flowering finishes.

When to Cut Back in Spring

Spring is an important time to prune chrysanthemums. Here are tips for the best spring pruning schedule:

• Wait until the last frost has passed and new growth emerges, usually early to mid spring.

• Prune in late morning on a dry, sunny day to reduce disease risks.

• Remove any remaining dead stems left from winter down to 1-2 inches above the soil.

• Also trim back healthy stems by 1/3 to 1/2 their height, making cuts just above outward facing leaf nodes.

• Early to mid spring pruning invigorates growth and shapes the plants.

The exact timing depends on your climate and variety. Late April to early May works well for most regions. Just avoid pruning too early while cold snaps are still possible.

When to Pinch Back Stems in Summer

In addition to spring and fall pruning, pinching mums during summer encourages branching for fuller plants:

• Begin when new spring growth reaches 4-6 inches long.

• Use your finger and thumb to snip off 1-2 inches from the tip of each stem.

• Make cuts just above leaf nodes so no bare stubs remain.

• Repeat every 2-3 weeks until around July 4th in most regions.

• Later pinching removes potential flower buds. Stop 6-8 weeks before your desired bloom time.

• Pinching mimics grazing by animals and triggers more stems to grow from the plant’s crown.

• Pinching is complete when mums are around 8-12 inches tall and filled out.

Time summer pinching to shape plants before they grow lanky and flop over.

When to Prune Chrysanthemums in Fall

Fall is when your prudent spring pruning and summer pinching pays off with a cascade of colorful blooms. Here are fall mum care tips:

• Prune leggy plants one last time in early fall to reshape if needed. Remove up to 1/3 of the height.

• Cut back 6-8 weeks before your expected first frost date. This ensures you don’t mistakenly remove emerging flower buds.

• Stop deadheading once flower buds swell, usually 4 weeks before frost. Let some buds mature to focus energy into flowers.

• Stake tall or weak stems to support flower heads using soft plant ties.Insert stakes 8-12 inches from the ground.

• Leave fresh pruning wounds exposed to maximize air circulation and prevent diseases. Avoid overcrowding.

• Remove spent blooms and faded flowers regularly to improve appearance.

Properly timed fall pruning and staking results in compact, prolific flowering that lasts into fall.

Regional Pruning Timelines

The ideal pruning timetable depends partly on your USDA Plant Hardiness Zone’s growing season length:

Northern Zones 3-5

• Spring: Late April to Mid May
• Summer: Mid June to Early July
• Fall: Early to Mid August

Midwestern Zones 5-6

• Spring: Mid April to Early May
• Summer: Early June to Mid July
• Fall: Mid August to Early September

Southern Zones 7-9

• Spring: Mid March to Late April
• Summer: Late May to Mid June
• Fall: Late July to Mid August

Adjust dates based on your local weather and variety. Later blooming types can be pruned later.

Pruning Young vs. Established Chrysanthemum Plants

Age and maturity make a difference in mum pruning needs:

• First year – Prune sparingly, just shaping and pinching to encourage establishment. Wait until second season for rejuvenation pruning.

• Second year – Prune actively to shape, thin, and improve flowering. Remove up to 1/3 of oldest stems in spring.

• Third year on – Prune more aggressively, removing up to 1/2 of oldest stems in spring to rejuvenate overgrown plants.

• Also prune anytime plants become overgrown, woody, or declining. Severe pruning renews old plants.

You can be more aggressive with pruning as mums become well established. Harsh pruning is tolerated once the root system is mature.

What to Do After Chrysanthemums Finish Flowering

Mums give one last push of energy into bloom production in fall. Follow these tips once they finish flowering:

• Cut back spent flower stems to 2-3 inches above the ground. Leave fresh wounds exposed.

• Keep watering until the ground freezes but reduce frequency as plants go dormant.

• Add a layer of organic mulch like chopped leaves or straw around the base after the ground freezes to insulate roots.

• Cut back any remaining dead growth in late winter before new growth emerges.

• Dividing large clumps every 2-3 years in spring rejuvenates old plants. Replant the healthiest outer pieces and discard old centers.

Proper care after flowering allows plants to recover and store energy for next year’s growth.

Troubleshooting Chrysanthemums

If your mums fail to thrive and flower abundantly, pruning may be partly to blame. Here are some potential issues and solutions:

• Few or no flowers: Pruning too late removed flower buds. Stop pruning 6-8 weeks before frost.

• Leggy growth: Pinch stems earlier and more often to force branching.

• Flopping stems: Cut back overly tall stems in early fall. Stake tall varieties.

• Small leaves and thin stems: Prune stems less severely and ensure adequate sunlight.

• Dead branches: Prune damaged stems immediately and improve air circulation.

• Late bloom time: Choose earlier blooming varieties. Stop pruning earlier before frost.

Adjust your timing, technique, and variety selection to solve common mum problems.

Achieving Success with Chrysanthemum Pruning

Learning when and how to properly prune chrysanthemums removes much of the mystery and frustration from growing these flowering favorites.

Follow the pruning timeline that fits your climate, pinch mums during summer, and discontinue pruning in early fall to allow blooms. Prune carefully using proper technique. Select varieties suited for your region as well.

With some practice, you can prune mums like a pro and be rewarded with voluminous color in your autumn garden for years to come. Soon neighbors will be asking for your secrets to glorious garden mums!