Why Your Garden Mums Are Dying

Why Your Garden Mums Are Dying

Short Answer: Garden mums, or Chrysanthemums, are popular fall flowers known for their vibrant colors and variety of bloom forms. They’re great for adding autumnal color to gardens, containers, and cut flowers. They prefer well-draining soil, full sun, and regular watering. While often treated as annuals, with proper care, including mulching and winter protection, they can be perennials in some climates.

Gorgeous garden mums in shades of red, yellow, orange, purple, and white pop up everywhere in the fall. Use them for autumn displays on your porch, along with dried cornstalks, gourds, and pumpkins. After the flowers finally finish blooming, you might be tempted to plant them in the garden since most fall mums are perennials that survive the winter. But by the following spring, plants may be reduced to clumps of dead stems.

After checking in with a few mum-growing pros, we discovered that planting mums late in the fall isn’t the best idea. In general, garden mums are pretty easy to grow once you know the following common mistakes to avoid.

How Long Do Mums Bloom, and When Is the Best Time to Plant Them?

orange mums and green pumpkins during the fall season

Ignoring the Type of Mum

Amy Enfield, a horticulturist for Miracle-Gro, says garden mums should be planted outdoors by late summer or early fall so the roots have time to form before the soil freezes. Also known as hardy or Belgian mums, garden mums are sold in garden centers and nurseries. They’re perennials in USDA Zones 5 to 9. But even when planted at the right time, they need a few other things, like excellent drainage. Enfield adds, “There’s no guarantee they will survive the winter, particularly the further north you live in the U.S.”

Enfield explains that florist mums, the kind sold in the houseplant section of your local grocery store, aren’t meant to transplant at all. “Unlike garden mums, these are meant to grow inside as indoor potted plants and are not cold hardy.”

Planting in Too Much Shade

Cynthia Drumgool, a potted plants and mums manager with Ball Horticultural, says garden mums need full or partial sun. One exception: in very hot climates, mums benefit from shade during the hottest part of the day. wise, give them plenty of sun for plenty of blooms.

Over-Fertilizing Your Plants

You can give your plants fertilizer with nitrogen when they’re starting to grow leaves and branches in spring. But don’t fertilize once your mums form flower buds, says Enfield. Fall mums will benefit from a high-phosphorus fertilizer that promotes root development.

Forgetting to Water Mums

Enfield says one of the biggest mistakes you can make with fall-planted mums is failing to water them. “Days are cooler, the sun isn’t as intense, so plants, even those in containers, don’t dry out as quickly. However, plants will continue to require water until the ground freezes.” While you may need to water daily in the summertime, water only when the top inch of soil feels dry to the touch after the weather cools down. Do the same for potted indoor mums.

Cutting Garden Mums Back Too Soon

Enfield advises that you deadhead your garden mums in the fall but leave the rest of the plant alone for as long as possible. Fall mums use their leaves to turn sunlight into energy to form roots. Wait until the following spring to do additional pruning or until the stems die back to the ground. Then, cut the stems down to about an inch above the ground before new growth appears.

Pinching Mums Too Late (or Not at All)

If you don’t pinch the growing tips of your garden mums, they’ll bloom, but you’ll have plants with long stems and fewer flowers. “Pinching to remove flower buds helps encourage the plant to branch and become fuller,” Enfield says. “Stop pinching in early July (no later than mid-July) and allow the buds to form and flower.”

Not Improving Drainage

Mums won’t thrive in soil that drains poorly and stays too soggy. That’s especially true in cold winter areas, says Enfield. So if you have heavy clay or compacted soil, mix in some good-quality garden soil or compost to loosen it and improve the drainage in your planting site.

Finally, Enfield says that the fall mums now sold in garden centers aren’t the same kinds of plants sold 20 years ago. Although garden mums are considered hardy to Zone 5, breeders have developed fall mums with big mounds of showy flowers. This has resulted, she says, in plants that may not be as cold-hardy as in the past. So, if your fall-planted mums don’t come back like true perennials, treat them as annuals. Replace them with beautiful, fresh plants when you’re ready to decorate for fall, and enjoy their colorful blooms.

Frequently Asked Questions

  • Do mums come back every year?

    If you live where mums are hardy and you plant perennial mums, they should come back every year, but they must be adequately cared for to survive winter.

  • Are mums toxic to pets?

    Yes, according to the ASPCA, mums are toxic to pets. Keep pets away from them to avoid illness.

Most Popular Flowers & Plants in the USA

RegionPopular FlowersPopular Plants
Northeast (e.g., New York, Massachusetts)Rose, Purple Lilac, Mountain LaurelSugar Maple, American Elm, White Pine
Southeast (e.g., Florida, Georgia)Orange Blossom, Cherokee Rose, Southern MagnoliaLive Oak, Spanish Moss, Saw Palmetto
Midwest (e.g., Ohio, Illinois)Carnation, Violet, Purple ConeflowerBur Oak, Prairie Grasses, Wild Bergamot
Southwest (e.g., Texas, Arizona)Bluebonnet, Saguaro Cactus Flower, Indian PaintbrushJoshua Tree, Agave, Mesquite
West (e.g., California, Washington)California Poppy, Coast Rhododendron, BitterrootGiant Sequoia, Redwood, Manzanita
Rocky Mountain (e.g., Colorado, Montana)Rocky Mountain Columbine, Bitterroot, Indian PaintbrushBlue Spruce, Aspen, Sagebrush
Great Plains (e.g., Kansas, Nebraska)Sunflower, Goldenrod, Purple ConeflowerCottonwood, Bluestem Grasses, Buffalo Grass
Pacific Northwest (e.g., Oregon, Alaska)Oregon Grape, Forget-me-not, Pacific RhododendronDouglas Fir, Western Hemlock, Ferns

This table includes the most popular flowers and plants in the USA by region, which considers a range of botanical species, including native and widely cultivated varieties.

Most Popular Flowers & Plants in Australia

RegionPopular FlowersPopular Plants
New South WalesWaratah, Bottlebrush, Flannel FlowerEucalyptus, Acacia, Banksia
VictoriaCommon Heath, Waxflower, Pink HeathMountain Ash, Silver Wattle, Victorian Blue Gum
QueenslandCooktown Orchid, Golden Penda, Umbrella Tree FlowerMoreton Bay Fig, Macadamia Nut, Queensland Bottle Tree
South AustraliaSturt's Desert Pea, Kangaroo Paw, Eucalyptus BlossomAdelaide Blue Gum, South Australian Blue Gum, Saltbush
Western AustraliaRed and Green Kangaroo Paw, Mangles Kangaroo Paw, Swan River DaisyJarrah, Marri, Karri
TasmaniaTasmanian Blue Gum, Leatherwood Flower, Tasmanian WaratahHuon Pine, Tasmanian Oak, Myrtle Beech
Northern TerritorySturt's Desert Rose, Frangipani, Desert RoseBoab, Gidgee, Spinifex
Australian Capital TerritoryRoyal Bluebell, Australian Daisy, CorreaSnow Gum, River Red Gum, Black Mountain

This table offers a basic overview of popular flowers and plants in each Australian region, focusing on a combination of state flowers, native species, and other characteristic plants. It's important to note that specific species' popularity and prevalence can vary. This table is a simplified representation. Consulting local botanical gardens or regional horticultural societies in Australia would be ideal for more detailed and accurate information.

Charlotte Gammon

By Charlotte Gammon

Meet Charlotte Gammon, our expert and author. She's our true treasure, as she has got 20+ years of experience in gardening, winery and house design. In early 2000s, she worked for today.com magazine and was in charge of the gaardening section. Later on, Charlotte opened her own designer agency and worked as a designer and decorator. We are happy to have Charlotte with us, as she is our good friend. We value her experience and we're sure you will love the articles she created for our blog.