How to Care for Potted Mums After They Bloom So They Continue to Thrive

Many may toss their chrysanthemums once they've provided those first pops of autumn color. However, your potted mums can last well through Thanksgiving and can even be transplanted into your garden as perennials.

So how should you care for these flowers after they've bloomed? Here, experts break down how to extend the lifespan of these fall beauties as well as where to store them for the winter.

Best Care Practices

Frankie Gniwodda, founder of Frankie’s Flower Farm, grows thousands of dahlias and mums every season for florists and markets and has had her fair share of trial and error keeping potted mums alive and healthy. Sunlight and water are perhaps the two biggest factors. 

“Mums are thirsty plants, especially in pots,” she says. “I check them daily and water once the top layer of soil feels dry, but I avoid letting them sit soggy. They also do best with plenty of sun at least half a day. If they’re too shaded, the blooms fade fast.”

Another factor to consider is temperature control. “Chrysanthemums require cool conditions and a cold wintering period,” says Maksim Kazakou, resident botany expert at Plantum. “During flowering, maintain temperatures between 61 and 65 degrees Fahrenheit.”

How to Deadhead

Deadheading ensures your mum’s energy is directed at making new growth and greatly increases the life and beauty of your plant throughout the season. Gniwodda waits until the blooms are fully spent and turning brown, then snips them off just above a set of healthy leaves. “I do this regularly,” she says. “The more you keep up with deadheading, the more fresh buds you’ll get.”

For cultivars with small flowers, simply pinch off the flowers with two fingers. Once the mum has fully flowered for the season, Kazakou says to cut back all stems, leaving stubs about two inches tall. “Make the cut just below the flower,” he says. “The angle of the cut doesn’t matter.” 

Where to Store for Winter

At the end of the growing season, after the mum has finished flowering and its leaves start to die, cut back all stems.

“Then, place the plant in a cool spot between 38 and 41 degrees Fahrenheit for winter dormancy,” Kazakou says. “This can be a balcony, basement, fridge, or porch. The temperature mustn’t drop below 32 degrees, as most potted mums aren’t cold-hardy.”

During winter dormancy, the soil should be slightly moist, but not completely dry. “If you live in a region with mild winters or your potted mum is cold-hardy, you can move it to open ground,” she adds. “As for non-hardy varieties, you can grow them outdoors during the warm season. Dig them up and bring them indoors for overwintering.” 

Don't Miss

How Often to Water Mums for Vibrant, Long-Lasting Blooms All Season

Can Mums Survive Frost? Here's How to Protect Them From a Dangerous Cold Snap

How to Transplant

The best time to plant potted mums into open ground is spring, once the late frosts are over, says Kazakou, or four weeks before the first frost in the fall. 

“When planting your mum in open ground, consider your climate and the plant’s winter hardiness,” he says. “The most cold-hardy are Korean mums, while Indian mums are less hardy and may not survive temperatures below 37 degrees Fahrenheit. The multiflora mums fall in between in terms of hardiness.”

Chrysanthemums can grow in most soil types, as long as they’re well-draining. Don’t plant mums in areas where water accumulates, especially during winter, and be sure the spot receives enough sunlight. Kazakou suggests this step-by-step approach:

1. Prepare the ground: Remove any surrounding weeds and loosen the soil, then dig a hole slightly larger than the root ball.
2. Move your mum: Carefully remove the plant from the pot without damaging the root ball, then move it into the planting hole and fill it with soil.
3. Give it a drink: Water your mum well after it’s secured.
4. Provide it with cover: Mulch the soil around the plant. You can use wood chips, straw, or other organic mulch.

During the growing season, Kazakou recommends complex fertilizers. “Generally, this plant needs nitrogen fertilizers during the first half of the growing season,” he says. “In the second half, you should opt for phosphorus and potassium fertilizers. To stimulate growth and strengthen your plant, use a 2 percent solution of succinic acid.”

How to Repot

Typically, potted chrysanthemums need to be repotted once every year after winter, says Kazakou. If your plant shows signs of root damage, it’s best to repot it immediately. Here are his instructions: 

1. Select your container: Choose a pot an inch wider than the plant’s root system, and be sure it has drainage holes. Place a layer of drainage material, such as expanded clay, at the bottom of the pot—at least an inch thick.
2. Prepare new soil: You can use an all-purpose potting mix, but add 10 to 20 percent fillers like perlite or vermiculite. This will improve the soil's structure, making it breathable and moisture-retentive, which is crucial for the proper development of the root system.
3. Remove your mum: Carefully remove the plant from the pot, making sure the root ball stays intact. 
4. Treat root rot, if needed: If the root system has been damaged, carefully untangle the root ball, remove the old soil, cut off any rotten roots, and treat the root system with specialized root rot solutions. You can use biological products based on Bacillus subtilis and Trichoderma sp., which are good for both treatment and prevention.
5. Add soil and water: Fill the free space with fresh soil, gently compacting it. Water the plant afterward.