Why You Should Buy Perennial Mums Instead of Annuals (and Where to Find Them)

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As the summer season winds down, gardeners like myself start getting desperate to hang onto blooms in the garden. At the same time, mounds of annual mums in pots fill the grocery stores and big box stores, marketed as the perfect gift. But mums are annuals: They’re going to croak when the first frost hits, making them a very short-term investment.  What many people don’t realize is that perennial chrysanthemums, sometimes called “show mums," are a giant, perennial showstopper version of those sad grocery-store mums. 

Perennial mums are a better investment

While there are thousands of flower types, there’s a specific kind of showy flower that is quite popular—giant zinnias and dahlias all have symmetrical flowers that are all over the color spectrum. If you like zinnias and dahlias, then perennial mums are absolutely going to float your boat. They’re a little harder to find, so you want to be sure you’re asking for the perennial kind.

Remember, annual flowers like zinnias will bloom for one season and then the plant will likely die at the end of the season, and the plant won’t come back again. However, a perennial like dahlia or perennial mum will die back, but then come back year after year, and will usually grow in size and volume.

Mums serve a great purpose in that they fill in late-season color in your yard. They're cold hardy, and will fill in the spaces of the garden where other plants have died back for the season.

How to find perennial mums 

The easiest way is to go to a specialty mum purveyor like Heritage Mums, which only sells mums, and has a wide variety of them. Since specialty houses like Heritage sell out early, check with your garden center for pots of perennial mums.

The same way there are types of zinnias and dahlias, there are a variety of types of chrysanthemums. Spoon mums have curled petals with an open end, while spider mums have crazy string-like petals. Incurve mums are glorious big balls of slightly arced petals that curve inward.

Mums don’t require a lot of specialized care

Cynthia Stringham, who owns Heritage Mums and grows every single mum they sell each year, talked me through how to care for these show mums. Usually, they will arrive as “plugs," a small two-inch plant with some roots. After you harden off your mums, you’ll want to plant them in a sunny spot in well-balanced, loamy soil. Incorporate compost and slow release fertilizer into the hole the mum is planted in. While mums enjoy light fertilizer treatment while growing, once buds form, cut off the fertilizer. While mums tolerate partial shade, you won’t get the same bloom production, so ensure at least six hours of sunshine. Mums like moisture, but shouldn't be overwatered; well-drained soil will help ensure the plants aren't water logged. Plants should be one to two feet apart. 

If you have cold winters, you’ll want to add some protection to your mums by mulching over them. In the most extreme cases, you may want to dig your mums up and keep them protected inside. 

There are tricks to ensuring more mum blooms

The key to a lot of mum blooms is pinching back your plant. You do this to encourage something called “branching": Instead of having a few stems, you want to encourage as many stems as possible. By cutting the plant back many times over the summer starting in July, you will encourage the plant to grow more stems, by branching out where the cut is. 

Mums, like dahlias, benefit from support. You can use stakes or netting, but to keep plants from flopping over, get trellising in early. To get the best cut flower, you can harvest mums when the bloom is almost all the way open.