How to deal with mums:
Ruth Shaw asked,
What do I do with my Chrysanthemums when they quit blooming?
I am writing this with the expectations of being able to refer people to my blog instead of answering it six times a day. You can plant and grow mums in the garden outside. Here’s how it works:
A lot of beautiful mums were sold in the months of September and October. Chrysanthemums are fun to watch and grow. There is a trigger for the blooms on most plants. Crape myrtles bloom with the effects of temperature. Azaleas bloom after their flower buds have gone through a period of cold followed by a period of warmth. (This excludes the Encore azaleas which are different—more about these in a separate blog.).
Chrysanthemums respond to a phenomenon called “photoperiodism”. This means that their blooming is regulated by day length (photo=light + “period”). Mums grown in an unregulated environment will bloom naturally in the fall. They will develop their vegetative growth in the summer months and then form flower buds in August and September. There are many different varieties that bloom earlier or later. The professional growers will produce several of these varieties in order to extend the selling season. For seasonal mums at the nursery, rooted cuttings are planted in pots somewhere around the first of July and are “pinched” to form branching until about August 15, timing depending on variety. The fully branched plants are then grown out into the specimens that you see at nurseries, grocery stores, and flea markets.
Poinsettias also set their bloom by the number of hours of daylight/darkness.
Florist mums are grown differently. Special and fancier varieties are grown in a greenhouse in which the light may be regulated. This is commonly done by pulling a shade cloth over the plants at a certain time of day. The production of florist mums is highly specialized and takes quite a bit of knowledge, talent, and educated labor.
Chrysanthemums are perennial plants and should grow and return anywhere south of the Mason Dixon line. I’m not quite sure how far north they will survive, but they do will here in north Georgia and my mother grows them in Kingsport, Tennessee.
When your chrysanthemum quits blooming cut off the spent blooms. Cut the tops of the plants down to 2/3 of the plant’s original size. Keeping in mind that mums like lots and lots of light, prepare a space in the garden. Due to photoperiodism, you will want to find a place that is not under or near a street light or other long burning outside lighting fixture.
Shake the pruned plant out of the pot and look at it. Most growers will put two or three or more plants in the pot, depending on the pot size. You may divide these if desired, or you may just choose to plant the entire plant as it comes from the pot. If you wish to divide the plant, carefully slide a butcher knife between the individual plants and cut the root ball.
It is important that you break up the root ball of the plant so that the roots will grow out and into the soil instead of remaining in a tight ball that is caused by the flower pot. Don’t be afraid to be a little rough with the roots.
The rest is easy, dig a hole, add some organic material, add a teaspoon, more or less of Osmocote, cover the roots, pack the dirt down, and water when needed.
For growing out the following spring, you should cut back the dead stems from the year before and watch the little plants grow. Prune the plants around July 1 and then again around August 1-15. This will encourage branching which will give you more blooms. During active periods of growth, fertilize the plants every couple of weeks with a little liquid feed. This will supplement the effects of the Osmocote.
I found out by accident one time that you should leave the dead stems all winter and remove them after the plant starts to grow again in the spring. This seems to insulate the new shoots from the cold.
Florist mums that have spent their lives either inside a greenhouse or in another warm environment may not do as well as the garden mums. If you take a plant out of the warm house and plant it outside in the winter time it won’t have time to become acclimated to the cold and will probably croak. These plants will probably do better if kept in a warm, bright window until spring.
By the way, did you know that you can bonsai a chrysanthemum? I think there is a chrysanthemum bonsai society. I’ve never done it, but I have seen some beautiful pictures.
Enjoy the planting
John P. Schulz