How-to Guide
Overwintering Fall Mums
The short answer
It depends on which mum you bought. True garden (hardy) mums are root-hardy perennials in roughly USDA zones 5-9 and can come back for years; florist mums — the lush gift-plant types — are far less cold-hardy, and Iowa State Extension says most will not survive winter planted outdoors in a cold climate.
Even garden mums bought and planted in fall often die over winter, because they don't have time to root in. Spring-planted garden mums survive far better; Virginia Tech Extension notes late-August/early-September planting is about the latest that still allows root establishment.
To give any mum its best odds: leave the dead stems standing over winter (research shows survival is better with old growth left on), then after the ground freezes hard, cover the crown with 3-4 inches of loose, airy mulch such as straw or pine needles. Cut back and uncover in early spring.
Garden mums vs florist mums
Fall garden centers and grocery stores sell two different things under the name "mums." Garden mums (hardy mums) are bred to be perennial and overwinter in roughly zones 5-9. Florist mums are bred for big indoor flowers, not cold survival — Virginia Tech Extension describes them as not hardy when subjected to freezing, and Iowa State Extension says most florist mums planted outdoors will not survive an Iowa winter; the few that do often have their flower buds killed by frost before they can open.
If the tag doesn't say, assume a September grocery-store mum in a decorative pot is a florist type — enjoy it as a long-lasting annual, or overwinter the pot in a protected spot like a cold frame or unheated garage rather than expecting it to establish in the border.
Planting time decides survival
The dirty secret of fall mums is that even hardy varieties usually die their first winter when planted in October — they simply haven't rooted in. Iowa State Extension states that mums planted in late summer or early fall often do not survive the winter, and that spring planting gives the best establishment. Virginia Tech puts the practical cutoff for fall planting at late August to early September so roots can develop before the ground freezes.
So if the plant matters to you, buy hardy garden mums in spring, plant them in full sun and well-drained soil, and treat fall pots as decor with a possible bonus if they pull through.
Winter protection: don't cut, do mulch
Leave the plants standing. Iowa State Extension reports that garden mums survive better when the old growth is left through winter — the dead stems trap insulating air and snow and reduce crown damage from freeze-thaw heaving. Don't cut back until spring.
After the first hard freezes (Iowa State suggests late November or early December; Virginia Tech says after the first hard frost), mulch over the crowns with 3 to 4 inches of light, airy material — straw, pine needles, loose shredded bark, or evergreen boughs. Avoid whole leaves, which mat down and smother the crown. The goal isn't to keep the plant warm but to keep the frozen soil frozen, preventing the freeze-thaw cycles that heave shallow-rooted mums out of the ground.
Spring cutback
Pull the mulch off in early spring — late March to early April in the Midwest, by early-to-mid April in Virginia — once the danger of severe cold has passed. Then cut last year's dead stems back to the ground; new shoots emerge from the crown. From there, the usual mum routine applies: pinch or shear the new growth until around early July for compact, bud-loaded fall plants.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Iowa State University Extension — Growing Chrysanthemums in Iowa — Most florist mums won't survive winter outdoors; late-summer/fall-planted mums often don't survive; garden mums overwinter better with old growth left standing; mulch several inches of straw/pine needles late Nov-early Dec (leaves mat down); remove late March-early April
- Virginia Cooperative Extension — Overwintering Mums — Garden mums (Chrysanthemum x morifolium) hardy zones 5-9; florist mums not hardy when frozen — protect in cold frame/unheated space; plant by late Aug-early Sept for root development; 3-4 inches light airy mulch (pine needles, straw not hay, evergreen branches) after first hard frost; remove by early-to-mid April; leave stems until spring