Chrysanthemums, also known as mums, are a favorite fall flower for many reasons. They’re bold, beautiful, and their sweet and spicy scent creates an alluring autumn aroma. They come in a variety of vibrant colors, including yellow, white, orange, burgundy, bronze, purple, and pink. Mums are hearty flowers that can withstand cooler temperatures, and although they can start blooming in late summer, they burst into life during the fall season.
Mums make a wonderful addition to your front porch display and fall flower beds. Below, learn how to care for mums so you can keep the flowers looking radiant all season long—and year after year.
How to Care for Mums
Mums are resilient flowers, and you can extend their life with proper care and even help specific types become perennial rather than annual flowers. Keep reading for all of their care requirements.
“Most mums are now grown in greenhouses because they’re ‘picky’ with lighting conditions,” says Amber Noyes, Horticulturist, Ecologist, and Executive Editor at GardeningChores.com. “If you grow them outdoors, they need full sunlight, which is at least 6 hours of bright light a day on average.”
Noyes says that indoor mums do best with bright, indirect light. “Mums are also photoperiodic, which means that they blossom only when the hours of light are just right,” she says. “In fact, they will bloom in autumn or fall, because they will flower when they have 16 hours of darkness and 8 hours of daylight, which are the optimal conditions.”
Mums do best in well-drained loam-, clay-, or sand-based soil when planted outdoors. “In containers, you can use a potting mix of 1:3 good quality potting soil, 1:3 coarse sand or other draining material, and 1:3 peat moss or coco coir,” Noyes says. “The ideal pH should be between slightly acidic and neutral.”
Tammy Sons, horticulturist and CEO of TN Nursery, says that mums require a lot of irrigation because they’re in direct sunlight. “Water once a day, in the evening hours,” she says. “This is vital because watering them in the mornings doesn’t give the soil adequate time to soak up the moisture before the sun pops out and dries it up, sometimes leaving the plants moisture starved.”
Noyes also advises making sure the water penetrates 6 to 8 inches into the soil if they’re planted in the ground. In containers, they need about 1 inch of water a week. Check the soil to see if it’s dry and water accordingly.
Temperature and humidity
“Chrysanthemums are cold hardy to USDA gardening zones 5 to 9,” Noyes says. “Some varieties, like Mammoth Daisy, will tolerate even lower temperatures, down to USDA zone 3.”
She says that if you grow mums indoors or in a greenhouse, the minimum temperature for them is 20 degrees F, and the maximum is 90 to 95 degrees F. The optimal temperature for chrysanthemums is between 62 and 72 degrees Fahrenheit.
“Mums also like humidity, and ideally, it should be between 70% and 90%, which is easy to obtain in a greenhouse, but less so indoors,” Noyes adds. “So, if you grow and care for mums at home, aim for 40% to 50%; anything under this will cause them to suffer. The humidity level will also affect their mass and growth, and consequently, their blooms.”
Noyes says that mums also need feeding, but it depends on where you grow them and which fertilizer you use. In containers and with a liquid fertilizer, you should do it every month, but start at least a month after you have planted the seedlings and stop before the flower buds open.
“With slow-release fertilizers, you should do it every six to eight weeks, starting at least a month after planting and stopping before they bloom,” Noyes says. “Outdoors, it depends on how fertile your soil is; in a well-kept organic garden, you may need to compost it when planting them, and maybe later in the season, a few weeks before they blossom.”
Sons suggests using liquid Osmocote because it’s gentle and effective. “Apply once monthly during the active growing seasons for big, bold, and beautiful blooms,” she advises.
Types of Mums
The Chrysanthemum genus includes about 40 species. Here are the most popular types of mums, according to the experts:
- Anemone Chrysanthemum—These mums have a raised cushion-like center.
- Quill Chrysanthemum—These have long tubular-shaped petals.
- Spider Chrysanthemum—These have elongated petals that resemble spider legs.
- Irregular Incurve Chrysanthemum—These mums are distinguished by their florets that curve upward towards the middle of the flower, and the lower petals that form in an irregular pattern.
- Reflex Chrysanthemum—These mums have florets that curve downward, and the bloom’s center is slightly flat.
- Regular Incurve Chrysanthemum—These mums have petals that curve upward into a tight ball or sphere shape.
- Intermediate Incurve Chrysanthemum—The petals on these mums are loosely curved upward and are not as tightly shaped as the regular incurve mum.
- Pompon Chrysanthemum—These mums have globular-shaped petals that incurve and completely cover the center of the flower.
Noyes says you will need to prune your mums multiple times to have profuse blossoms and round shrubby perennial plants.
“The first pinch, as we call it, is around the end of May,” she says. “The plant should have grown by about 6 inches by then, and you should cut it down to 2 to 3 inches to promote lateral shoots.”
Then, when the new shoots you have promoted have reached about 6 inches, she says to cut them again to 2 to 3 inches tall. “You can keep doing this till mid-July,” she says. “Then you need to stop because your mums will be producing buds, and lots of them.”
After the mum has blossomed and the flowers are spent, Noyes says it’s time to prune the plant much more drastically. As soon as the leaves are yellow and start to dry up, cut it down completely to almost ground level at about 2 to 3 inches tall.
If you want to propagate your garden mums, it’s best to do it in the springtime. You can propagate mums from seeds, cuttings, or division. Noyes says most people prefer to grow mums from seedlings, which you should plant in your containers after the last frost, which is usually between May and early June.
To propagate and care for mums from cuttings, you should cut stems over 4 inches tall at a 45-degree angle and pluck leaves off an inch from the bottom of the stem. Then, dip cuttings in a root hormone and plant in a perlite and compost mixture. It will take a couple of weeks for roots to grow, and then you can transplant them into larger pots or into your garden.
Dividing mum plants is one of the best ways to propagate them. You remove the mum from the container or dig it up and cut the plant and roots into sections with a sharp knife. Make sure each section has roots and replant them into containers or in your garden.
Growing From Seeds
“If you want to grow your mums from seeds, use trays with good quality and well-drained, fine potting mix about six to 10 weeks before the last frost is expected,” Noyes advises. “In most places, this means between February and March.”
She says you should keep the soil humid but not wet and at about 70 to 75 degrees F to see the seedlings appear in 10 to 21 days.
Then, move them to a place with lots of indirect light, and make sure the seedlings have hardened off before you plant them in your containers or garden.
Growing in Pots
Many mums that are sold in pots from stores are typically florist mums. This means they aren’t as hardy as garden mums, so they typically don’t survive through harsh winters. You can check the care tag to see what gardening zones are listed so you know which type it is.
Gardening mums thrive in zones 5-9, and florist mums can only withstand temperatures of zones 7-9. If you purchase a gardening mum, you can transplant it to a larger, well-drained container and bring it indoors during the winter so you can plant it in the spring.
Remember, mums love sunlight, and indoor mums do best with bright, indirect light. Also, make sure to water them thoroughly, as they are thirsty plants.
Mums are cold hardy, but you still need to protect them against frigid temperatures. Spread a layer of mulch or straw around the base to help them survive the winter.
If your mums are in pots, you should bury them in the ground and layer them with mulch, or you can bring them indoors to prevent them from freezing. This is how to care for mums during the winter so they will become a perennial rather than an annual flower.
While mums are healthy perennials, they can be affected by pests and diseases, especially in wet conditions. The common pests and diseases Noyes warns about are:
- Chrysanthemum aphids: These pests suck on young buds and foliage. Spray garlic water on your mums to get rid of them, to avoid pesticides.
- Leaf miners: These are larvae of many insect species that live inside and eat the soft tissue of the foliage of your mums. Most people manage these by spraying vegetable oil on them.
- Mites: Feed on leaves, but you can send them packing by spraying a 1:1 mixture of alcohol and water and then wipe the leaves with a paper towel.
- Fungal infection:, You will see a powdery mildew and leaf rust, which you can easily cure by spraying a mixture of 1:10 neem oil and water on both sides of the leaves and on the stems.
- Foliar nematodes: These are parasites that live inside the leaves, and they cause dry and dark patches at first, but they can cause lots of foliage death if unchecked. These are very hard to treat. Cut all the damaged leaves and dispose of them to start with. Some gardeners pour hot water, at 122 degrees F, over the plant for 5 minutes, but it can damage your plants, and you may need to give up on this year’s profuse blossoms.
Common Problems with Mums
Here are some other common problems with mums:
- Lanky and floppy stems, which are caused by too much shade. Cut them back and move your chrysanthemum to a brighter spot.
- Stems are too woody, due to poor watering.
- Discoloring of leaves, which is usually due to lack of nutrients and poor fertilization, or too much watering, unless you have a fungal infection.
When Does It Bloom?
Mums have long blooming cycles but typically bloom in late July and through October. Since there is less daylight in the fall, it makes them bloom during these months.
Frequently Asked Questions
Are mums pet-friendly?
Mums are toxic to dogs, cats, and horses if ingested. According to the ASPCA, they can cause diarrhea, vomiting, hypersalivation, dermatitis, and incoordination.
What does chrysanthemum mean?
“Chrysanthemum” comes from the Greek words khrusos (gold) and anthemon (flower), so it means golden flower.
Do mums come back every year?
If you care for garden mums properly, they are able to bloom yearly. Make sure to protect your mums during winter months so you can enjoy them every fall.