Happy Thanksgiving! The table is set and the aroma of roasting turkey fills the air. You hear the doorbell and go to answer it. Sure enough, your dinner guests have arrived bearing pumpkin pies, hearty appetites… and a potted chrysanthemum.
Familiar as corsages and potted gift plants, chrysanthemums are the iconic fall bloomer. Available in a wide range of colors, from white through yellows to reds, pinks and purples, there is a shade for every garden. Orange, russets and golds are particularly appropriate for this time of year. Forms vary just as much. Spider mums have long petals forming shaggy heads, while others resemble simple daisies. Most garden varieties have double flowers such as the ones pictured here. All in all, the US National Chrysanthemum Society recognizes thirteen bloom types. The flowers are supported by stiff stems approximately two feet high and adorned with elongated heart-shaped gray-green leaves with uneven edges.
What to do with your gift plant? Chrysanthemums are easy to grow, both in containers and in a perennial border. Normally, you’d set out transplants or divide existing plants in late May, so you might have to overwinter your mum indoors. Once the bloom has faded, keep it barely moist, in a cool spot where it won’t freeze. The garage is fine if you’ll remember to water it occasionally. It’s all right if the leaves fall off—that’s normal for a perennial in winter.
Next spring, water the plant well, let it drain, then remove the roots from the pot and place them in the ground, in well-drained soil amended with compost and a time-release fertilizer. Or, you can replant it into a larger pot with a commercial soilless potting mix.
Full sun increases bloom and reduces the likelihood of powdery mildew on the leaves. Irrigate to keep a bit moist, but don’t let their roots sit in a puddle. And remember, mulch is always a good idea.
Pinching the ends off of the growing stems encourages branching, keeps plants compact, and increases the number of flowers. Stop once summer arrives, however, so that flowers have a chance to bloom before the season ends.
Once cold weather has killed the top growth, an additional eight inch layer of fluffy mulch or evergreen branches will help these USDA Zone 5 perennials survive the winter, especially in colder areas.
Mums are susceptible to a variety of insects and diseases, including Verticillium wilt, septoria leaf spot, spider mites, aphids, leafhoppers, leafminers, and the above-mentioned powdery mildew. Be sure the problem is correctly diagnosed before reaching for any pesticides.
Excellent border perennials, chrysanthemums also do well in containers where they can be moved to center stage during their season of bloom season. Companion plants might include sedums, ornamental grasses, and dwarf evergreens as well as other perennials.