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To overwinter dahlias, dig up the tubers and stash them in a shoebox

A clump of tan-colored dahlia tubers, which resemble small sweet potatoes, covered in soil.
Maksims Grigorjevs
Dahlias can be replanted year after year, but their tubers aren't hardy enough to overwinter in the soil. You can dig them up and store them for the winter and plant again next spring.

Dahlia blooms grow well in Vermont's climate, but they are too delicate to overwinter in the ground. Now is the time to dig them up and get them cozy for a long winter's nap so you can plant them again for more blooms next spring.

If you grew dahlias this year — those gorgeous, pom pom-like flowers that come in red, yellow, peach and more — you were most likely treated to a beautiful crop. And the flowers may have lasted longer with the warmer temperatures this fall. Now is the right time to save those dahlias to overwinter and plant again next spring.

Dahlias are not hardy enough to make it through Vermont's winter in the soil, so you'll need to dig up the tubers and get them tucked away for a few months.

The tubers look almost like small sweet potatoes and are connected in a clump under the soil. To remove them, first begin by cutting back all the foliage on the dahlia plants. Next, dig up the entire clump of tubers from the soil. Remove any tubers that look damaged, and then wash off any large clumps of soil.

Next, place the clump of tubers in cardboard or wooden boxes. Metal trays or racks work well for storage, too. Keep the boxed-up tubers in the garage for a day or two, to let them cure and get used to being out of the soil. They are going to be dormant for the winter and need to harden up a bit.

When a day or two has passed, add some wet wood chips into the boxes along with the dahlia tubers. This allows airflow along with a bit of moisture which will keep the tubers plump instead of dried out. Place the boxes in a basement or an unheated garage which stays above freezing, but below about 45 degrees.

Leave the box of dahlia tubers nestled in wood chips throughout the winter and periodically check them. If the tubers look a bit shriveled, mist them with a bit of water. If any start to mold or rot, pull them out and clean them, then put them back in the cardboard box, making sure there is still sufficient airflow.

Ready them for replanting in spring by pulling out the boxes and emptying out the wood chips. Take a good look at the dahlia tubers. If any have sprouted eyes on them (just like the ones you might be used to seeing on potatoes) divide them up and plant again.

Q: Charlie, since my garden had grown jumping worms this summer, I haven't roto-tilled in a few years. Should I till it now before planting winter rye? I was wondering if that might help kill off any eggs. — Bette, in Rockingham

A: Unfortunately, tilling the soil is not going to kill the jumping worms. The adult jumping or "snake" worms will die off in the winter but their eggs will survive in the soil.

More on jumping worms from Vermont Public: Learn to identify invasive worms and remove them from your soil

By tilling that infested soil, all it will really do is mix up the eggs but won't get rid of the worms.

The best course of action is when it warms up next spring and you begin to work in the soil again, hand-pick any adult jumping worms you see (and keep removing them!) and get rid of them that way.

Q: I have a Sungold cherry tomato plant. The fruit went from green to partially gold and then it goes to black. It's not blossom-end rot. It is total fruit black. What is that? — Sharon, in Burlington

A: As the growing season comes to an end in Vermont and colder days become the norm in fall, a lot of tomato plants that still are green and have a few fruits left on them will go through this color change. Many tomato varieties will experience this: the skin coloring of the fruit begins to ripen and then will deepen to a blackish color.

The good news is that this doesn't represent a tomato plant blight or disease, necessarily. More likely, it is the cooler and shorter days of late autumn that turn the tomatoes black.

You can still eat the fruits, but they might not be the best-tasting or have the most pleasant texture!

All Things Gardening is powered by you, our audience! Send us your toughest conundrums and join the fun. Submit your written question via email, or better yet, leave a voicemail with your gardening question so we can use your voice on the air! Call Vermont Public at 1-800-639-2192.

Listen to All Things Gardening Sunday mornings at 9:35 a.m., and subscribe to the podcast to listen any time.

Mary Williams Engisch is a local host on All Things Considered.
Charlie Nardozzi is a nationally recognized garden writer, radio and TV show host, consultant, and speaker. Charlie is the host of All Things Gardening on Sunday mornings at 9:35 during Weekend Edition on Vermont Public. Charlie is a guest on Vermont Public's Vermont Edition during the growing season. He also offers garden tips on local television and is a frequent guest on national programs.