When Is the Best Time to Plant Mums? The Answer May Surprise You

Chrysanthemums often appear for sale at your local garden center or grocery store long before summer is over. But hold onto your pumpkin spice latte—when is the best time to plant mums? A favorite for outdoor fall decor, mums burst into bloom just when many other summer-flowering plants like zinnias and petunias start winding down in the cooler autumn weather. 

That's why a few potted mums perched on your porch seems like a no-brainer for transitioning from summer into the next season. But don't be in too much of a hurry if you want your plants to last. Even though retailers start selling mums well before fall begins, you may want to hold off on buying them just yet.

Mums prefer cooler temperatures, which can be a problem if you buy them when they're first available and it's still getting to 90°F during the day. In the heat, all the flowers will fade in only a couple of weeks, so you'll have to replace them faster if you want to keep up a colorful show through the season. 

If you wait until things cool off before setting out your mums, you'll be treated to blooms for up to 8 weeks once the plants are in place. And if you get a few warm days here and there after cooler weather arrives, you can stash your mums in your house or garage until temps drop again.

Yellow Potted Mum ($26, Walmart)

Two other factors to consider are the type of chrysanthemum you're buying and where you want to use it. If you're simply hoping to use mums as an annual in a potted display or garden bed, you can opt for florist (or cutting) mums. Enjoy them until the blooms die off, and then compost them.

Hardy (or garden) mums are a different story. These mums are perennials as long as they're correctly planted and given the right care, making them a good choice for brightening up your fall garden. They're best planted in the spring once the ground is free of frost, giving them time over the summer to establish their roots in the soil before they become knockout bloomers in the fall.

They likely won't survive the winter in colder climates if you plant garden mums in the fall. Instead, you can try letting the plants go dormant in their pots and keeping them in a cold but frost-free indoor spot like a garage until the following spring. Then you can plant the mums outside in your garden once the soil has warmed up. If your plant is still alive, you should soon see new growth appearing from the roots.

For either type of mum, choose mums still budding and not in full bloom when picking out plants. You'll be able to enjoy their flowers longer this way.

The bottom line to the question "when is the best time to plant mums" is that there's no "best" time, but you'll get optimal plant performance in cooler weather. Mid- to late-September is ideal if you want to love your mums for as long as possible.