How to Care for Mums
Although most flowers fade as summer ends, chrysanthemums, aka âmums,â are the quintessential autumn flower. This hardy perennial is best planted in spring, blooming throughout the fall. Learn how to plant and care for mums so that they come back year after yearâincluding how to overwinter mums.
Chrysanthemum x morifolium is the Queen of the Fall Flowers, celebrating the season in jewel colors: yellow, lavender, pink, purple, red, bronze, orange, and white. Each bloom consists of tiny flowers called florets. Bloom forms range in size from pincushion petite to giant spiders, and there are hundreds from which to choose.
Mums generally grow to a width and height of 3 feet tall if they are pinched regularly during the growing season. Bloom time is determined by day length (12 hours or less!), and buds start forming then. Mums spread quickly if properly planted and spaced.
Are Mums Perennial or Annual?
Mums are hardy perennials best planted in early spring. However, those pretty mums sold in garden centers as fall decorations as often best treated as annuals; do not try to overwinter them as they weren’t bred to be hardy.
Do Mums Come Back Every Year?
Yes, if you plant a cold-hardy perennial that’s marked to withstand low temperatures, it will come back every year. Early spring is the best time to order and plant mums to give them time to grow strong roots, become well-established before winter, and grow into a more robust, full plant.
Southerners can enjoy the colorful displays of blooming mums twice yearly because the equal days and nights of temperature weather that cause mums to bloom happen in both the spring and the fall. Northerners must be satisfied with one show, in autumn.
Mums growing outdoors in Ohio. Credit: Catherine Boeckmann
Select a planting site in full sun, away from trees and big shrubs. Mums require rich, well-draining soil. They do not like standing water and will quickly rot if left too wet. Prepare by adding aged manure or compost to the soil (mums are heavy feeders).
Container Tip: Many folks will set their potted mums on or near their porch. Plants that receive light at night from security lights or street lights will be slow to bud! If you’re wondering why your mum isn’t blooming, it’s often due to this reason (as well as lack of sun or water).
When to Plant Mums
- Mums are hardy perennials best planted in early spring.
- Start mums indoors from seed 6 to 8 weeks before the last spring frost date.
How to Plant Mums
- Set mums 18 to 36 inches apart, depending on their expected size at maturity.
- Mums need good air circulation.
- Plant mums in the ground at the same depth that it was grown at in the pot. If planted too low, water can gather around the base and rot the stems.
- Water and keep it evenly moist.
- If you are growing mums in pots, they will be dry in no time and you must keep them moist; when you water, it should drain out the bottom. (If you buy mums in wrapped containers, make sure they have drainage holes!)
- Watering mums is important to success; too little water slows or stops their growth! Keep mums moist. Soak the soil deeply when watering. Avoid watering the leaves.
- Mums are heavy feeders. A monthly application of a balanced fertilizer (10-10-10) is good practice.
- Spread mulch around the mum to conserve soil moisture and to keep weeds out.
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Pinch back stems to create a bushier plant: When new shoots are 3 to 4 inches tall, pinch off the top, leaving 2 to 3 leaves on the shoot. Continue pinching every 2 to 3 weeks until mid July, when buds develop. On the West Coast, stop pinching in early July. In the South, stop in early August.
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Stop fertilizing when flower buds emerge.
- For big flowers, pinch off all buds except the largest and strongest on each stem. Remove secondary buds farther down the stem as they develop, too.
- Switch to a high-nitrogen fertilizer after buds have set. If flower size does not matter, stop fertilizing in mid-August.
- After the ground has frozen, spread 4 to 6 inches of mulch around the plant.
- Do not cut back mums in fall. The dead growth insulates the roots. Cut off the dead stems and leaves when you see the first green shoots in spring.
Overwintering Mums
USDA Hardiness Zones 5 and warmer, perennial chrysanthemums can be kept outdoors (in the ground) through the winter. But in extremely cold areas, overwinter plants in a basement or dark, cold closet. Pot up plants after the first frost in the fall, capturing as many of the roots as possible. Leave the foliage on the plants until spring.
Water well and keep the roots damp. Check pots weekly. In spring, gradually introduce the plants to light. Set them out after the last killing frost.
Dividing Mums
Every 2 to 3 years, divide mum when new growth appears in the spring. Use a knife cut out the old central portion of the plant. Discard it. Cut the remaining portion into sections. Each section should have several shoots and good roots. Replant these sections.
Mums belong to one of 13 classes are based on flower form and petal shape!
- Irregular Incurve: giant blooms, e.g., âBola de Oroâ (gold)
- Reflect: very large to medium blooms, e.g., âPretty Pollyâ (purple, with pink reverses)
- Regular Incurve: ball-shape, e.g., âGeorge Couchmanâ (bronze)
- Decorative: flattened, e.g. âCoral Charmâ (salmon)
- Intermediate Incurve: more open than other incurves, e.g., âSt. Tropezâ (crimson, with bronze reverse)
- Pompom: balls, e.g. âKevin Mandarinâ (deep orange)
- Single and Semidouble: concave/convex, e.g. âDomingoâ (crimson, with yellow center)
- Anemone: single, e.g., âDaybreakâ (apricot, with yellow center)
- Spoon: single/daisy with tipped ends, e.g. âKimieâ (yellow, with green center)
- Quill: tubular florets, e.g., âKing’s Delightâ (true pink)
- Spider: varying florets, e.g., âLavaâ (yellow, with red tips)
- Brush or Thistle: upright florets, e.g., âWisp of Pinkâ (yellow center)
- Unclassified or Exotic: irregular, e.g., âLone Starâ (pure white)
Extra-hardy Mums
These will survive survive in frigid climates: âBetty Louâ Maxi Mum, âBurnt Copperâ, âCenterpieceâ, Grape Glowâ, âLemonsotaâ, âMaroon Prideâ, âMellow Moon,â âMinnautumnâ, âMinnpinkâ, âMinnrubyâ, âMinnwhiteâ, âMinnyellowâ, âRose Blushâ, âSesqui Centennial Sunâ, âSnowscape’
Image: Pink Spider Chrysanthemum. Credit: EdenGardenGr.
Cut flowers for arrangements when they are nearly or fully open. Remove lower leaves that would be in water. Leaves submerged in water will rot. Change the water in the vase every couple of days. Vase life is 7 to 10 days.
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I was given a potted mum five years ago and have kept it blooming every year by "winterizing" it. I cover it with the cut dried up flowers and stems of the plant, add some leaves, cover with chicken wire (to keep all in place) weighted down with bricks. This spring, I was able to divide the plant into three and all three did well. I'm in zone 5, and some of our winters are brutal with cold and wind. This winter is forecast to be even worse, so time will tell how my mums survive it.
Potted mums purchased in autumn will often overwinter with little effort, at least mine do. I do repot them when I bring them home, however. Most people leave them in their plastic tubs and simply dispose of them after bloom. I look forward to a few hours in the cool garage in fall, potting up the new mums - there's always a new color that catches my eye, too. Standard, inexpensive potting soil, no need for fertilizer. I only buy mums that are just starting to bloom or have only buds - obviously, they last longer. When they are done blooming and repeated nightly frosts are likely, I take them into the garage: detached, unheated. I let the greenery fade a little, then I cut them down. There is always new green hidden at the base of the plant. The article suggests leaving the greenery and giving some water overwinter - I may try that on a few as an experiment this year, but previously I have not watered or left green. In spring, around mid-April, I just set them outside, give them a drink and wait. Within 2 weeks they are greening up again. Once in a while one might not return, but usually they all do if they are a single season old. I've had many, many that return for a third year! I know this is not supposed to happen, but it does! Now, they take all summer to keep growing and get buds. Mine from last year are just starting to flower now - some need another couple weeks. They usually double in size, too. It's fun remembering the colors I have as they open. A few big pots of greenery all summer are nice to place strategically around and I also like to keep a big grouping of them all together in another area, then bring them out front as they flower. Of course this will tie up your pots for a couple years but I have plenty of pots now. I still buy new mums yearly to replace the ones that won't make after a second or third bloom, so the pots get rotated. Give it a try, even with a few, just to see what happens!
This was extremely helpful! Thanks
I did the same exact thing one year. I planted potted mums from the supermarket along the border of the garden not expecting them to survive the winter but they did. They survived for 3 years until we had a very wet winter which killed them.
I'm not a gardener. I had a plant that I planted last fall, after the blooms were gone. I summer in PA, and when I returned here, the plant had survived the winter, and grown to about two feet. Should I cut it back? Do you think it will bloom again?
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