Winterizing and Planting Mums

Mums in Containers

Garden mums also make great container plants. They’re just right for popping into a clay pot, lining up in a row in a window box, or placing in the center of a mixed container with trailing foliage plants all around. Many landscape plants can provide a backdrop for groupings of mums. For texture, choose ornamental grasses or the neon purple berries of the beautyberry shrub (Callicarpa). You also can pair mums with smoke tree (Cotinus), variegated sedum, the deciduous dwarf Fothergilla gardenii, or almost any conifer.

To get the most from your mums, choose cultivars according to their bloom times. It also helps to coordinate bloom time with the length of fall in your location. Most garden mums will withstand a light fall frost, but finding the right cultivars will provide the longest possible amount of pleasure.

Annual or Perennial?

Mums aren’t as expensive as many perennials, so if you choose to, you can plant them as annuals without worrying that you’ve spent too much money on something that might not live more than one season. If you’re an impulse buyer, you’ll probably see pots of colorful mums this fall and not be able to resist.

Fall planting lessens the chance of winter survival, however, since roots don’t have time to establish themselves. If you want something more permanent and are willing to provide proper care such as mulching and pinching to encourage compact growth and more blooms, plant mums in the spring and allow them to get established in the garden. This will improve their chances of overwintering and reblooming the next year. Some plants will even produce a few blooms in the spring before being pinched for fall flowers.

Hardy vs. Florist Mums

Florist (or cutting) mums and hardy (or garden) mums come from the same original parent — a golden-yellow daisylike mum from China. Today’s hybrids in both categories are the results of endless crosses between several species from China and Japan. The result of such hybridization performed over hundreds of years is different types of mums that perform for two distinct purposes.

Florist mums are large-flower plants with many possible bloom forms, from quilled to pompon to spider and more. Grown in greenhouses and used only as indoor plants, florist mums produce few, if any, underground stolens, which are necessary if the mum is to survive cold weather. Florist mums planted outside are most likely being used as short-term bedding plants that will be removed when the blooms are spent. You can plant a potted florist mum you receive as a gift, and it may grow for the summer, but it will not survive the winter, no matter how much protection you give it. Garden mums, on the other hand, produce underground stolens and can survive cold better. Most garden mums are perennials in Zones 5 to 9 and much tougher than florist types. Some cultivars are less hardy than others and can be killed by an early spring frost.

Whether you’re looking for a quick splash of color or a fixture for your border, mums are the pick for a fabulous fall.

Growing Mums

When it comes time to plant mums, consider these factors:

Location. Choose a spot that gets at least six hours of sun a day. Plants that don’t get enough sunlight will be tall and leggy and produce fewer, smaller flowers.

Soil preparation. Mums thrive in well-drained soil. Heavy clay soil should be amended. If your yard is soggy after the slightest rain, grow mums in raised beds with friable soil for good root growth.

If the soil is too dense, add compost and prepare to a depth of 8-12 inches for best performance. Mums’ roots are shallow, and they don’t like competition. Plant mums about 1 inch deeper than they were in the nursery pot, being careful with the roots as you spread them.

Trim off the previous year’s stems as soon as the new spring growth begins to show.

Watering. Water newly planted mums thoroughly, and never let them wilt. After they are established, give mums about an inch of water per week. When bottom leaves look limp or start to turn brown, water more often. Avoid soaking the foliage, which encourages disease.

Fertilizer. Plants set out in spring should get a 5-10-10 fertilizer once or twice a month until cooler weather sets in. Don’t fertilize plants set out in fall as annuals, but plants you hope to overwinter should get high-phosphorus fertilizer to stimulate root growth.

See our favorite mums.

Overwintering. Prepare mums for winter after the first hard frost. Mulch up to 4 inches with straw or shredded hardwood. Fill in around the entire plant, spreading well between branches. Pinch off dead blooms to clean up the plant, but leave branches intact. Mums have a better chance of surviving if you wait to prune old stems until spring. As soon as the weather warms, pull away mulch to allow new shoots to pop up.

Dividing. Mums grown as perennials need to be divided every couple of years. Divide in the spring after the last hard frost and after you see new growth starting. Dig up the plant in one piece and separate outer pieces from the center with a clean sharp spade or large knife. Replant the outer portions into a rejuvenated bed, and discard the original center of the plant.

Pests. You may notice aphids, leafhoppers, or spider mites, but they are not likely to harm the plant.

Pinching Mums for Better Bloom

The key to those full, rounded domes of blooms that you associate with mums is pinching to create more branching and keep plants compact. Don’t hold back — just a few minutes here and there will reward you with a thick, solid-looking plant.

If you’ve bought large, full plants in the fall, they have already been pinched and are ready for planting. Young spring plants will need pinching for maximum bloom and best plant shape.

Start pinching as soon as you see a good flush of buds. Pinch about half of the tender new growth at the top of the shoot; choose some stems with buds and some without. Repeat the process with every 3 to 5 inches of growth (about every two to four weeks) until July 4. Stopping then ensures you will get good bud formation and blooms in fall.

Varieties to Look For

Look for these recently introduced cultivars at your local nursery.

‘Blizzard’ This extra-late variety offers the largest (2-1/2-inch) and whitest flower available in a daisy garden mum. It develops into an almost ball-shaped plant covered with bright white blooms over extra-dark green foliage.

‘Bold Felicia’ The early blooms are an unbelievable neon-hot pink daisy with a bright yellow center disk.

‘Carrie’ A hard-to-find two-tone decorative flower that is a dark red-bronze in the center with golden-yellow outer petals. This extra-late cultivar shows none of the discoloration of aging petals seen in some older varieties.

‘Melissa’ This extra-late mum blooms through late October and was bred for excellent flower form, flower color, color retention, and growth habit. The bright lavender-rose flowers combine beautifully with ‘Erica’, ‘Ingrid’, and ‘Taffy’.

‘Vicki’ Another bright “wow” of a plant, these decorative blooms are rich orange with a darker orange center. They have awesome color and a full spreading plant habit.

‘Zesty Jean’ An unusual pastel peach-coral color, the early decorative flowers are more fully petaled and retain their color longer than others of this hue.