Why You Should Think Twice Before Tossing Your Mums This Year

For weeks in the fall, cheerful pots of mums adorn front steps and porches next to piles of pumpkins. These are the season's most popular flowers for good reason—they provide a bright splash of color while the rest of the garden is turning brown. Sunny yellow, warm cinnamon, pastel pink, royal purple, rusty red—these are just a few of the available colors of chrysanthemums. Once those colorful blooms begin to fade, though, most gardeners toss the mums out.

It's a shame, because garden mums are usually hardy and can be replanted in the ground. Instead of wasting your mums on a repeating cycle every year, plant them in the garden to overwinter. Those mums will thank you by showing off their blooms next fall.

Types Of Mums

Most mums you pick up at the garden center or grocery store are hybrids that can be categorized into two general types: hardy garden mums and exhibitionist or florist mums. The former can overwinter in your garden, while the latter won't survive a freeze. So how can you tell the difference? First, check the tag to see if it lists hardiness zones—most garden mums are winter hardy in USDA Zones 5-9. Second, if you found your plant inside the florist shop or grocery store or wrapped in foil as a gift, the mum most likely is meant to be enjoyed in the short term.

Among garden mums, the most common types are compact and dense "cushion" mums. The flowers may be spidery or look like daisies, pom-poms, or thick cushions of slightly curved petals. Korean and rubellum mums grow lankier at 2-4 feet tall and look beautiful draped along a fence or in the middle of a flower border.

When To Replant Mums

It's better to plant mums in the garden early in the season so they have time to develop a root system for winter. Wherever you live, try to get them in the ground at least six weeks before the first heavy frost. If you miss that window, you can always give transplanting a try and see if your mums survive the winter and reward you next year. If the plant looks brown and dry, check underneath the dead growth first to see if they're alive. You should see some green growth right at the soil level.

How To Replant Mums

Chrysanthemums prefer rich, well-draining soil in full sun, though they can take a little shade in the South. Gather up a shovel and some compost and decomposing leaves if you need to amend your soil. You'll also need mulch or leaves to help retain moisture and keep the roots warm.

1. Prepare a hole that is the same depth and slightly wider than the root ball. If soil amendment is needed, first add compost and decomposing leaves to the garden soil. Add a 2-inch layer in that area of the garden bed and mix in well with a shovel.
2. Pull your mum out of the pot and loosen up the root ball with your fingers, especially any circling roots.
   
3. If your mum is bone-dry, give it a good soaking first, then place the plant in the hole. Fill in around it with soil and water thoroughly.
4. Cover the soil around your plants with an inch or two of mulch or leaves. Don't cut brown growth any shorter than 6 inches, as it will help protect the crown of the plant over winter.

Caring For Replanted Mums

Water your mums during dry weather as they were likely root bound and need help getting established. Once the weather grows cold, they won't need watering as frequently. If you're expecting a long, hard freeze, cover the crowns with a pile of leaves to help insulate them.

Again, leave at least 6 inches of dead growth in place until the weather warms in spring. Then you can use snips to remove the brown stems to the soil line and expose the green growth underneath. If you would like to fertilize, use a water-soluble, nitrogen-heavy fertilizer in spring. Once buds appear, switch to a bloom-boosting fertilizer that is higher than phosphorus.

Some mums will bloom early or grow rangy unless pinched. Pinch back the stems to about 6 inches long once the plants exceed a foot, usually in May and again in June or July. Then let your mum continue growing until it reaches its full fall glory.

Common Issues And Solutions

• Mums are fairly pest-resistant, but aphids do find them tasty. Remove the soft-bodied insects with a strong spray of water. You may need to repeat this every couple of days.
• Spider mites can stipple the foliage during hot, dry weather. Again, use a strong spray of water. Miticides can be effective with a difficult infestation.
• With leaf spot or powdery mildew, hand-pick and throw out diseased foliage. A serious problem may require spraying with a fungicide.
• Mums easily dehydrate, which leads to brown, crunchy foliage and flower buds. Watch for wilting and water when dry. Keep plants moist during the blooming season, but don't overwater, which can cause yellowing leaves and the spread of disease.
• Mums are toxic to dogs, cats, and horses, so don't plant them where your pets frequent.