Store These Seven Tender Bulbs Over Winter

Different tender bulbs and fleshy, underground stems like corms, tubers, and rhizomes require similar techniques to prepare them for winter hibernation. It’s important to check your weather reports for overnight frosts while keeping an eye on flower stalks, as dropping temperatures will kill them back. You’ll want to let the aboveground parts wilt and even blacken, but you don’t want to let a hard freeze turn your underground harvest into mush.

If you’ve never attempted the annual fall practice of storing bulbs, this guide can show you the common steps and plant-specific tweaks that will get your colorful bulb bank socked away for future enjoyment.

Overview

There are five basic steps to follow to store tender summer bulbs over the winter.

1. Watching for foliage die-back.
2. Digging up and letting them dry or “cure.”
3. Dusting off the dirt and placing them in a proper storage material.
4. Keeping them in a cool, dark, and dry place.
5. Checking on them once a month or so to monitor for over-drying or rot.

Key Details

• When curing, set bulbs on a cardboard lid or paper-lined tray.
• When storing, do NOT let bulbs touch. This is to avoid spreading disease. If one bulb is rotting, it can infect the others.
• If your bulbs are shriveling and in a storage medium like cedar chips, this means the bedding is too dry. Using a spray bottle, you can lightly mist the medium with water.
• Be gentle when you dig out bulbs. If using a shovel or spade, dig around the outside edge of where you think the roots are, then loosen and lift the clump out with your hands. If you have a hand rake, that’s even better — you’ll be able to get a little closer to the bulbs, but you still need to move gently to avoid scratching them.
• Each of the seven, popular summer bulbs listed here needs similar care, though some are fussier than others or do best when stored in a particular way. As you practice storing bulbs, you will likely develop your own ways of successfully getting them through the cold months depending on your climate. Here are some guidelines to get you started.
• Unlike seeds, which can be sprightly growers even after a couple years of storage, summer bulbs will die if they are not replanted in the spring.

Storage Tips

Here’s how to store different types of tender bulbs.

Gladiolus

These exuberant flowers, with their tall stem of alternating buds, are a delight to the eyes at the height of a steamy summer. Luckily, they’re pretty easygoing when it comes to storage, though you will need to cure their corms a bit longer than other tender bulbs.

1. Wait for their foliage to blacken after a frost.
2. Dig up the clusters of corms, then dry in the sun for two days.
3. Using pruners, cut back the foliage to two inches, brush off clinging soil, then lay the corms on a cardboard lid or paper-lined tray. Let the corms dry out for another three weeks out of direct sun in a warm, 60-70 degree F environment.
4. Remove the shriveled “mother” corm and toss. Snap off the tiny baby corms (cormels) — you can plant these separately from the larger ones in the spring, but it’ll take a few years for them to grow large enough to bear blooms.
5. Change the paper on the tray or put the corms in a new cardboard lid and store in a dry, dark area at a temperature between 35-45 degrees F.

Canna Lily

A subtropical ornamental, the canna lily is not a true lily, but is actually related to banana and ginger plants. For cooler temperate zones, it’s a treat to have this exotic flower blooming in the hot months. Storage prep methods for canna rhizomes are similar to gladiolus corms, but they require a cozier type of bedding.

1. When the leaves blacken from an overnight frost or hard freeze, dig up the rhizomes.
2. Cut back the foliage to six inches and set the rhizomes out to dry for two days.
3. Lightly rub the dried soil off the rhizomes.
4. Put a one-inch layer of cedar chips in the bottom of a bin. Layer the canna on top so that the rhizomes do not touch. Cover with another layer of cedar chips and repeat as needed.
5. Top the container loosely with a lid, but do not seal, as a little ventilation will help keep everything dry.
6. Store the bin in a cool, dry place such as a basement, with a general temperature of between 45-50 degrees F.

Calla Lily

No, this is not a true lily either, but a member of the genus Zantedeschia. Native to South Africa, calla lilies come in a variety of striking colors and add a modern elegance to potted and cut floral arrangements. What looks like their flower petal is actually a modified leaf that wraps around the center, where a spadix contains the actual tiny flowers. Like gladiolas, they grow from corms, and love a hot, sunny day.

1. After frost blackens the foliage, delicately remove the rhizomes.
2. Dry the bulbs for three weeks in a warm location, then remove the old stems and dust off any soil.
3. Store in a cardboard box or a paper bag between layers of slightly moist peat moss or vermiculite, and make sure that none of the rhizomes are touching.
4. Keep in a cool, dry place at 45-55 degrees F.

Chincherinchee

Not a lily or a Mary Poppins song, Chincherinchee is a bulb from the Hyacinthaceae family and another South African native. Also called Star of Bethlehem, this ornamental can last up to six weeks as a cut flower in a vase.

1. Following the first frost, trim blackened, dead leaves to 2 inches.
2. Dry the bulbs for three weeks in a warm, room-temperature environment.
3. Store in a dark, cool area on a paper-lined tray or open crate at 45-55 degrees F.

Tuberous Begonia

Beguiling begonias lend bursts of color to shady and light-filtered areas, their flower petals glinting as though filled with sparkles. The tender-stemmed plants must be taken out of the garden about a month into autumn or before the first frost.

1. In September, give your begonias a decreasing amount of water and stop fertilizer treatments so they will start the hardening process.
2. After the foliage turns yellow, the stems will loosen and fall off.
3. Very carefully dig up the tubers.
4. Let the tubers dry in a sunny spot for two weeks.
5. Place tubers in a perforated plastic bin or bag, carefully bedding them between layers of peat moss or vermiculite.
6. Store in a dark, cool place at 45-55 degrees F.

Elephant Ear

Boldly tropical, elephant ear makes a big statement in any garden. Their massive corms are sensitive to cold. While it cues them to go dormant, too deep of a freeze can lead to corm rot, so you’ll want to keep an eye on the outdoor thermometer and what the elephant ear’s leaves are telling you.

1. As soon as the tops die back after the first frost, dig the corms out of the soil. Wear gloves before handling elephant ear — the sap in the roots can be irritating to skin.
2. Cut back the foliage to three inches.
3. Set the corms out to dry in the sun for three days.
4. Brush off any remaining soil from the corms and clip off the small roots growing on them.
5. Store at 40-60 degrees F between two-inch layers of peat moss or pine shavings in a cardboard box.

Dahlia

There’s been a renewed interest in dahlias in recent years, with their wildly variable color combinations starring in wedding bouquets, home magazines, and cottage gardens. The tidily formed, multi-petaled blooms almost look unreal in their perfection. Saving their tubers for winter requires a little more vigilance.

1. Wait for two hard frosts (overnight freezing temperatures) before you dig them out. When the first frost blackens the leaves, cut the stems back to six inches. After the second hard frost, dig them out.
2. Rinse the tubers and pat dry with a kitchen towel. 
3. Give the tubers a little trim: snip back the stems to an inch and cut off the hairlike roots.
4. Let them dry for 24 hours.
5. Pack the tubers in large plastic bins filled with cedar chips or peat moss. Cover their lids loosely to allow air to enter and to avoid too much humidity forming, which invites rot and disease. 
6. Store in a dark, cool spot, around 40-50 degrees F

Frequently Asked Questions