How to Dig up, Divide, and Store Dahlia Tubers for Winter

how-to-store-dahlias-over-winter

At the Dahlia Shed in Middletown, Amy Rodrigues grew more than 540 dahlia plants this year. She plans to nearly triple that amount in 2017.

“They’re my girls, and I treat them like dairy cows,” says Amy Rodrigues, owner of the Dahlia Shed, of her beloved plants. “I’m a little more intense about it than most farmers.” This past season, she grew 540 dahlias, which are increasingly popular for weddings and other events. Next year she’s planning for 1,500 on the land she leases in Middletown. “The demand is insane,” she says. To get to that number, she’ll dig up, separate, and store this past summer’s yield.

If you haven’t dug up your dahlias yet, it’s hardly too late. Growers typically wait till two weeks after the first frost, when plants turn brown. If, like this year, there hasn’t been a frost by mid-November, it’s also safe to dig then. Tubers dug too early, however, will not store properly.

the-dahlia-shed-amy-rodrigues

Amy prefers to use a Spear Head Spade, available at Chaves Gardens, to dig up her dahlias. She plants, ties, and cuts all of the plants her field herself.

If you don’t want your cafe au laits mixed up with your pom pons, first label each plant by its variety. Next, cut the stalk to about 6 inches above the ground. Starting about a foot away from the plant, use a spade or pitchfork to gently lift the clump of tubers from the ground. Pull out the entire plant by its stalk, being careful not to break off tubers from the base; if one does get torn off, but has an eye like a potato, keep it. (The tube is the fuel source; the eye is what will sprout.)

Amy, who primarily supplies floral designers and also sells stems and arrangements from her driveway, prefers to remove dirt and stones immediately with a garden hose. If it’s a sunny day, do this somewhere cool, so the tubers don’t dry out. Allow them to air dry for 24 hours.

washing-dahlia-tubers

It’s easier to divide dahlias in the fall, when they’re soft, but if you don’t know how to identify the eyes, you can store the clumps whole. (It’ll be easier to see the sprouts next spring.) To separate tubers from a clump, Amy uses a hawk-bill shoe knife, though a sharp steak knife works just as well. Look carefully for an eye on each tuber; without one, the plant won’t sprout next year.

eye of dahlia tuber

Look for at least one eye on each tuber; without one, a new plant won’t grow.

The “mother” tuber on any clump – from which new growth will have sprouted over the summer – will be noticeably dark. These can be cut and tossed out. Also cut off any “rat tails,” which can cause rot. Allow the cuts to dry overnight.

dahlia-tubers-ready-for-storage

A clean and dry clump of dahlia tubers is ready to be stored or divided. Note that any cuts have already sealed.

To store the dahlias – whether in clumps or separated – use cardboard boxes or plastic bulb crates. Place a few layers of newspaper at the bottom of each, then add a packing medium such as cedar or pine shavings or vermiculite. Peat moss is okay, too – it provides excellent humidity for the plants – but can be messy.

Place a layer of tubers (or a whole clump) into the packing medium, spacing them far enough apart that they don’t touch. “If there’s rot, it will spread,” warns Amy. Continue to layer tubers and packing material into the container.

dahlias-in-vermiculite

Using a packing material like vermiculite helps keep dahlias insulated and disease-free.

Store your dahlias in a cool dry place between 40º and 50º F. A garage or storage shed is likely to be too cold. An unheated basement or root cellar is ideal, but keep containers off concrete floors and away from furnaces, which will dry them out.

During winter  months, check your tubers monthly. A bit of shriveling is okay, but if they look super dry, use a spray bottle to spritz them with water. Check on them during cold snaps; if they get too cold, they’ll freeze. Get rid of any tubers where you see rot like on an apple. A little white mold, however, can be removed with a paper towel.

Come mid-May, your tubers will be ready to plant. “They’re pretty hardy little son of a guns,” says Amy. “Once you start growing them, you begin to get obsessed. It’s kind of a disease.”

This article is the first in a new series of Expert Tips. Photos by Caroline Goddard.

You Might also like: Garden Tour: The Additon’s Dahlias, Wickford, R.I.

organge dahlia how to store dahlias

dahlia cafe au lait dinnerplate

the-dahlia-shed-newport-ri

You might also like: Garden Tour: Doris Duke’s Rough Point, Newport, R.I.

dahlia-tubers-and-how-to-store-them

amy-rodrigues-dahlia-shed

how to cut and store dahlia tubers

At the Dahlia Shed farm in Middletown RI

dahlia-shed-cat

dahlia-bright-red-pom-pon

You might also like: 5 Plants to Add to Your Garden for Beautiful Bouquets

Meaghan O'Neill is a writer, editor, blogger wrangler, and the founder of Puddingstone Post. She was formerly editor-in-chief of TreeHugger, Discovery Channel online, and TLC's Parentables. Her writing has appeared in numerous print and online publications, and her book, Ready, Set, Green: 8 Weeks to Modern Eco-Living (Villard/Random House) was published in 2008. She lives in Newport, RI with her family.

Be first to comment