Ever heard of Dendranthemas? Me, neither. They used to be one of the types of Chrysanthemums but that genus was split in 1961 and now we have this new term for them. Other terms include “perennial chrysanthemums” and “hardy mums” as opposed to what are sometimes called “florist mums.”
I became interested in this new name and the plants behind them after discovering them in the Behnke’s Perennial Department the other day. From the photos on the signs, they resemble daisies and indeed daisies used to be in the same genus before the “splitters” of the hort nomenclature world got hold of them and declared them something else. (They like to keep us on our toes.) Other dendranthemas have double flowers and that look exactly like the mums we’re used to seeing this time of year.
These tough perennials are deer-resistant, great for cutting, and bloom from early fall until frost on 3′ tall bushes. The plant can be made shorter and bushier by cutting them back half-way or even sheared to the ground (advice varies) in early summer – before July 4. They can also be kept at their best – and shared with friends – by dividing them every three years or so.
About those “Florist Mums”
But how about the common mums we see everywhere in the fall, the ones that are so often tossed, grown only as annuals? I asked Carol Allen about them and she swears that they come back every year for her*, so come to find out, they’re perennial, too. In subsequent years they won’t be quite as short and full as they are when you buy them because they were carefully raised to look that way, but if you cut them back once or even twice before that July 4 date, they’ll do very well in your perennial garden.
Just a few of the color choices available.
Posted by Susan Harris
*That said: Carol can grow just about anything successfully, with her ten green fingers and can-do spirit.
Our experience with overwintering of “florist” mums is variable. If they are in a very well-drained soil and it’s neither a soggy winter or a severe winter with very cold spells with no snow cover, your mums may come back. If so, the new shoots will form a ring/circle around the site of the original plant. In March, take clumps from the ring, about three inches in diameter, and plant these out where you want your mums. You should get a half-dozen easy; that is, if you get any at all.
This article was updated October 2018.