KC Gardens: Why don’t mums planted in autumn live past winter?

One of the problems we see a lot with mums that are grown and planted in the fall is that they don’t survive the winter.

There are a couple of reasons for that. First, a lot of mums are bred to show very big flowers with lots of color. When that happens, they’ve lost some of their winter vigor.

Another problem is that their root systems aren’t very strong and winter-hardy. So if you buy these mums in full color in the fall and plant them, they’ll often die over the winter.

You can help mums live through the winter by making sure they’re kept well watered through the fall and into the winter, and applying a light layer of mulch to insulate and protect their root systems.

But if you really want mums to come back year after year, defer buying them in the fall. Instead, buy small cuttings in the spring. Plant them in the spring and allow them to develop strong root systems over the summer that then bloom naturally in the garden.

When fall comes, you’ve got the color, and you also have a plant that is well-rooted and durable, and is more likely to survive the winter.

People often ask, “If the mum is not going to survive the winter outside, can I bring it inside and hold it over the winter?” There are a couple of problems with that. For one thing, there isn’t enough sunlight to keep the plant going in homes.

You may want to try to set it in your garage. That will keep it buffered from the extreme temperatures. Water it sparingly, and then there may be a chance that it will overwinter in the milder conditions.

But if you want the mums to come back year after year, it’s best to plant them in the spring. The fall-planted ones are just for color.

This story was originally published September 20, 2014 at 8:43 PM with the headline "KC Gardens: Why don’t mums planted in autumn live past winter?."