I like some mums and I cannot lie. We often purchase chrysanthemums (“mums”) as potted plants to give a little short-term color to fall displays. But once the blooms fade, do we toss them? Leave them? I say we should pull them up quickly to retrieve them! They’re actually perennials (plants that live for many years) and many can be taken out of their pots and grown in the landscape.
First know there are three types of mums. “Football mums” have very few but very large blooms. The plants tend to be tall and upright, lending themselves to cut flowers. They’re bred for that and pruned that way; they’ll tend to get leggy after a while. “Florist mums” or “pot mums” also have somewhat large flowers an upright growing habit. They’ve been bred and pruned to grow this way too. Neither of these types of mums do especially well in the garden.
However, “garden mums” have smaller and more numerous blooms. Their growing habit is lower than the other varieties and they have a rounded shape. So gardeners, if the mum is round… okay; you get the idea. You can see the shorter, rounder shape will hold out in the garden better. They’ll eventually grow to no more than about 12-18” tall. (If yours end up reaching for the sky, you can tie them in a bunch with string for support when blooming.)
Like most plants, they want a fertile, well-drained bed. Pick a spot with at least 6 hours of sunlight per day. Though the shortening days in fall that stimulate blooming, the plants will handle that themselves when the time comes. Cut the plant back by about ¼ to 1/3 of its original height and leave about 12” between plants. This will give some room for the vegetative growth needed to support new blooms later.
Turn the soil over, either with a tiller or a shovel. Then cover it with 2-4” of organic matter – compost, decaying leaves, or whatever’s available. Mix it into the soil, but there’s no need to fertilize this time of year. Just water them in and let them settle.
In January you can do some heavy pruning. Cut the mums down then to about 3” tall. You’ll see new shoots begin to sprout in February or March. Especially on older plants, you may gently dig it up and divide it into as many as four plants. You can then re-plant the divisions into beds prepared similarly to the fall-planted ones. This will promote vigorous new growth in spring.
Since they’ll be growing again at this point, apply some general purpose fertilizer. A balanced one like 8-8-8 will work fine, or you can use slow-release fertilizers, or whatever you use on your other flowers. It’s a good idea to cover the surrounding area with mulch. It will keep weeds down and reduce the need for watering in summer.
Though mums usually bloom most spectacularly in fall, it’s not uncommon for many varieties to put on a spring show as well. If this is the case, prune the dead flowers back after they bloom. This is called “deadheading”, and it keeps the plant from wasting energy trying to make seeds. We’d rather see it put that effort into growing over summer, eventually creating a wonderful display fall after fall.
If you want to know more about gardening, landscaping, or anything else horticultural, contact the St. John, St. James, & St. Charles Parishes County Agent André Brock at firstname.lastname@example.org. Also, the LSU Ag Center’s website can be accessed at www.lsuagcenter.com with lots of user-friendly information, including this article.