Why can’t I get ‘hardy’ mums to overwinter?
If you’re like most folks you buy ‘hardy’ mums in the fall, use them for decorating with pumpkins, hay bales and cornstalks and then, because you can’t stand to throw away a perfectly good plant, and it’s supposed to be hardy, you plant it.
The problem isn’t that the plant isn’t hardy enough, because if it is labeled as a ‘hardy’ or ‘garden’ mum, it probably is perfectly hardy. It’s the planting time, and most likely the drainage, that is at issue!
First, hardy mums need to be planted in the spring or early summer in order for their roots to become well established by fall and able to withstand the rigors of our zone 5 winters. Planting in September or October simply will not allow the roots to grow sufficiently.
The other thing that hardy mums need is sharp drainage. A rock garden or a dry location, such as those preferred by sedums, lavender and perovskias, suit mums just fine. They do not like to have damp roots during the winter.
So what do you do if you just can’t resist those beautiful bloomers? Well…give this trick a try. Plant ‘em in large containers, 3-5 gallons or so, keep them watered well for the fall. Then around Thanksgiving, put them in a garage or sheltered location for the winter. Give them about 1 cup of water per month. In the spring bring them outside, trim them back, and water well. Look for signs of life i.e. little buds at the base of the plant. If so, congratulations! Your mums have made it thru the winter. Now you can plant them in their special spot in your garden. Or…leave them in the pot, fertilize them, pinch ‘em back as outlined below, and you’ve got an instant fall decoration for next fall!
So, which mums are hardy in Zone 4?
We recommend Dendranthema’s (these have recently been reassigned to Chrysanthemum) which are perennial mums and are very hardy in zone 4. They do bloom very late in the season. Usually around the end of September.
- Chrysanthemum x Hillside Pink Sheffield (pale peach-pink single, 24”-36”h),
- x Campfire Glow (intense red/orange bicolor single, 22”-26”)
- x Mary Stoker (rose-tinted, apricot yellow, 24”-36”h)
- Chrysanthemum Autumn Crescendo Series (all about 18”-24”h) includes:
- Bolero (large, single, deep gold)
- Harmony (single, sunny yellow)
- Rhumba (coral red)
- Samba (light peach to pink)
- Dendranthema Igloo Series (all about 18”-20”h, most are double flowered)
- Warm Igloo (bronze, orange, yellow)
- Sunny Igloo (yellow)
- Frost Igloo (pure white)
- Cool Igloo (rich, raspberry)
- Rosy Igloo (rosy red)
How do I take care of mums in the garden or containers?
Mums are easy to grow if they are planted early in the growing season, in full sun, and given a very well-drained site. They hate having wet feet in the winter! Fertilize them with a liquid fertilizer up to 3 times during the growing season or top dress with a slow release fertilizer (about 1/4 cup for a 3-5 gallon container) soon after they start to grow in the spring. Pinch them back several times before the 4th of July to maintain a shorter, more compact habit. Pinching too late in the season will result in fewer flowers.
Mums are tough plants when they in their ‘happy place’, so give them what they want, and be rewarded with those beautiful blooms for many years to come.