5 tips for keeping your fall mums happy, healthy and beautiful

Those fall mums look so good at the garden center or grocery store that you splurge on a few big pots for your front porch.

But after a couple of weeks, they no longer look so good — the blooms are browning and the unopened buds are drying out. What did you do wrong?

Probably nothing, according to gardening experts.

The colorful mums make excellent cut flowers and attract pollinators to the garden into late fall, according to Carol Papas, a Penn State Master Gardener. Mums are photoperiodic, meaning that they’re stimulated to bloom when the number of daylight hours is decreasing. Avoid planting them near a streetlight or a light source that might inhibit bud production, she said.

“I hate to say it, but a lot of times they are finicky,” said Michelle Kubrick, co-owner of Kubrick Brothers Garden Center in New Kensington. “Most varieties bloom once and they’re done. Once the flowers open, they should bloom for two to four weeks, but that depends on good old Mother Nature.

“If we have cooler days and nights, they’ll last longer. If it’s 80 or 90 degrees, they’ll dry out quicker,” she said.

Commercially grown plants are not always hardy in the first place, because they are force-grown, said Carla Rusnica, president of the Greensburg Garden Center. The typical potted mum, short for chrysanthemum, also will be rootbound when you buy it, she said.

“Because they’re rootbound, they need a lot of water,” Rusnica said. “Once they dry out, the buds dry out, and they won’t flower. Trim the bad buds, so they don’t suck the moisture away from the good buds.”

Shirley McMarlin | Tribune-Review

Clip any dried buds off your fall mums to help keep the rest of the flowers blooming strong.

Finicky though mums may be, there are a few ways to help them stay lush and vibrant for as long as possible. Here are five tips from thespruce.com:

• Choose a strong plant — Look for plants with deep green, healthy leaves and many more buds than open blooms. Ask at the store when a new shipment arrives and try to buy plants on that day, before there is a chance that they will be neglected.

• Repot when you get it home — Most plants bought in pots will be rootbound, which makes it hard for the soil to retain water. Use a container that is a little bigger than the one the mum came in. Jostle or break up the roots, and then fill with soil to an inch from the top of the pot. Tamp the soil in and water until it flows out of the bottom of the pot.

• Find a sunny spot — Mums should have a minimum of four hours of direct sun per day.

• Water generously — If you don’t repot your mums, water may run through the roots and not be absorbed. Repotted or not, daily stick a finger into the soil to the second knuckle to see if the soil is dry, or pick the pot up — if it’s light, it’s probably dry. Besides watering from the top to rehydrate dry soil, you can put the pot in a bucket with a few inches of water and let it soak for a few hours.

• Deadhead the spent blooms — Not only will the plant look better, but it will last longer and maybe even repeat bloom.

Kubrick and Rusnica say they’re not necessarily sold on the idea of repotting mums, since the effort might not make that much difference to the life expectancy and health of the plant, if you keep it well-watered.

“A lot of people just put them out early and replace them when they turn brown,” Kubrick said.

Save or toss?

Similarly, they say it’s possible to try to overwinter them by planting them — but there’s no guarantee of success. After they’ve finished blooming, trim them back to the ground and cover with mulch.

“Most of the time they don’t survive these winters we have,” Rusnica said. “If they were rootbound, there’s not enough time for the roots to regrow and be deep enough in the ground. Once they freeze, they won’t get moisture.”

“It might not be something you want to spend time and money on,” Kubrick said.

If you’ve bought a mum with a color you particularly love, there’s another way to try to save it for the next year, Rusnica said.

“Take a piece or two and plant them in a root medium. Keep them in a bright window and try to keep them over the winter,” she said.

But the best advice, Rusnica says, is this: “Buy your mums and enjoy them now. I always think, I can buy another one for $5 next year.”

“Hardy garden mums are the perfect addition to your garden — an enticement to go into the garden during the crisp sunny days of fall,” Papas said.

Shirley McMarlin is a Tribune-Review staff writer. You can contact Shirley at 724-836-5750, [email protected] or via Twitter .