Can Fall Potted Mums Be Planted Outdoors at Season’s End?

Potted mums are everywhere in the fall, and with good reason. Mums, short for chrysanthemum, close out the gardening season in style. But after potted mums have served their purpose, can they be planted outdoors?

There’s certainly nothing wrong with enjoying potted mums in autumn, and then letting go. But those of us with a thrifty “can I get it to regrow?” attitude find the temptation too great to resist.

Bringing potted mums indoors to grow as houseplants is difficult. Plus, some of the fall mums are huge.

Potted mums might survive in the perennial flower garden, although they often do not, because mums sold in the fall vary greatly in winter hardiness. If mums are seriously wanted in the perennial bed, choose mums with greater winter hardiness like the Mammoth or Minn series, both developed by University of Minnesota, and are best planted in spring from starter plants sold at locally owned garden centers.

The potted mums sold in fall are many different varieties, and their winter-hardiness is usually unknown, and often untested in our hardiness zones. Some gardeners have recycled their potted mums by planting out into the perennial bed after enjoying them on the doorstep, and they’ve survived winter to become a great flowerbed addition. Other gardeners report negative results.

If you’d like to plant your potted mums into the flower garden to see if they will ‘perennialize,’ follow these suggestions:

• The sooner they’re planted before the ground freezes solid in early November, the better, as they’ll have some time to ‘root in.’
• Full sun is best, and choose a protected spot that gets good winter snow cover.
• Add a little organic material to the soil as you’re planting, and water thoroughly after the mum is planted.
• Leave the tops intact over winter, rather than cutting back. Mums survive winter better with tops left on. Cut back in early spring before new growth emerges from soil level.
• Add protective mulch in early November, after we’ve had killing frosts and frost has cooled the ground. Add 12 to 24-inches of leaves, straw, woodchips, peatmoss or compost to cover the plant and the surrounding soil. Don’t protect too early, as the mums can rot if the soil hasn’t cooled enough from penetrating frosts.
• Cross your fingers, and hope for the best.
• Uncover mums in early spring, around early April before new growth starts. Cut tops back to an inch or two above ground level, and hopefully new growth will emerge in late April or early May. That is also the time to divide established mum plants, creating even more.

Good luck, and have a great gardening day!