How to Propagate Mums for an Endless Supply of Fall Blooms

It just isn't autumn without the iconic presence of mums. Not only do these bright and colorful blooms add cheer to the fall landscape, but they're very cold-hardy to boot. Since mums are both beautiful and practical for the chilly months, you may consider adding even more to your garden—thankfully, it's easier than you'd think.

Propagating mums is a quick and simple way to plant more of these orange, yellow, and pink flowers. Ahead, our experts outline three different methods for garden mums—plus, how to care for them after they've taken root.

From Division

First, let's consider division. "The easiest and most successful way to propagate garden chrysanthemums is through division," says Laura Irish-Hanson, a horticulture educator at the University of Minnesota Extension. "You simply need to dig up the plant, and place the root ball on the ground; then, using a sharp spade or shovel, cut the entire plant in half or thirds—depending on the size of the original plant." Once divided, the new mums can be replanted in the soil.

From Stem Cuttings 

Another way to propagate mums is to cut stems from an existing plant. While this method can be effective, it's also more complicated, and can be less successful than propagating by division. 

"Garden chrysanthemums can be tricky to successfully propagate with stem cuttings," says Irish-Hanson. The horticulture educator doesn't generally recommend propagation by stem cuttings for several reasons, including disease and lack of success.

Regardless, if you want to give this method a try, then it's a good idea to do so in early summer, before your mums form flower buds. Create a miniature mist room if you can, too—a forsythe pot works especially well. Most importantly, make sure to use clean, sanitized pruners to take the 6 to 8-centimeter stem-tip cuttings. From there, follow these steps, as outlined by Irish-Hanson:

1. Wrap the Cut Ends

Immediately wrap the cut ends in moist toweling or a cup of water. Remove all leaves from the bottom half of the cuttings. Dip or roll the base of the cuttings into a 1500 parts per million (ppm) Indole-butyric acid (IBA) rooting hormone.

2. Plant the Cuttings

Immediately stick the cuttings into your rooting environment. Make sure the substrate, like vermiculite, remains moist, but not overly wet until roots form. Be prepared for many cuttings to never root and die, as garden chrysanthemums are notoriously finicky to propagate by stem cuttings. 

3. Transplant the Roots

Once roots are 3 centimeters or longer, you can transplant them into a regular potting mix for more fertilizer and rooting space. Slowly expose the plants to the outdoor environment, just as you would for hardening-off seedlings in the spring. Finally, transfer these well-rooted plants into your garden. Make sure to water them in well.

From Seed 

Planting from seeds is relatively easy, but you're in for a surprise when it comes to the color of the flowers. When propagating from divisions or stem cuttings, you know exactly what the genetics are and what colors to expect—but planting from seed produces a unique chrysanthemum, not a clone, so your new flowers can be very different!

"Last year I had three garden chrysanthemums self-seed into my front garden bed, and this year I have hundreds of seedlings," says Irish-Hanson. "Currently, I'm selecting the ones I want to keep based on their flower color. So, if you don't mind getting something different than your original plant, try seeds! If you want a specific color and form, stick to asexual propagation, like division."

If you don't mind a bit of chance, then definitely give this method a try. Follow these steps and you'll have a garden full of many colorful mums in no time.

1. Watch the Seeds

First and foremost, don't deadhead your mums at the end of the growing season in the fall. Let the blossoms dry out instead. Once the seeds look brown and dry, you can harvest them—they're very tiny!

2. Preserve Carefully

Over the winter, make sure to keep your seeds dry, out of direct sun, and at normal room temperature (or a little cooler).

3. Transplant

if you live in a region with a short growing season in the spring, then you may want to start the seeds indoors, in trays. Fill the trays with seed-starting mix and sow one seed per cell. Keep them in a warm location with plenty of light. Once the last frost date has passed, you can transplant the young mums into their permanent garden or container location. 

How to Care for Propigated Mums

Set your newly propagated mums up for success with ideal conditions and care. If you're working with stem cuttings, for example, make sure to use root hormone. "To make them root faster, dip the stem in water, and then dip it in some root hormone in a small bowl," says Jan Johnsen, landscape designer and principal at Johnsen Landscape and Pools. "It improves rooting success—and rooting occurs faster."

Mums love lots of sun, so place them in a location that gets 4 to 6 hours every day. Careful and regular watering is essential to keep the soil moist. "As with any newly propagated plant, you should make sure they're planted in the right environment," says Irish-Hanson. "Don't let the roots dry out too much between waterings."

Think carefully about which varieties you're propagating as well. "If you live in a harsher, northern climate with cold winters, make sure you only propagate hardy mums," she adds. "Annual mums likely won't survive."