How to Dig and Store Tender Bulbs for Winter
Don’t let cold winter weather ruin your tropical dreams. Save bulbs of tropical plants over winter. We’ll show you how.
Outsmart Old Man Winter by saving bulbs of frost-tender plants over winter and planting them again next spring. It’s not a tough job, and you don’t need any special knowledge or tools to succeed. Use this technique with plants that aren’t winter hardy in your zone. Good candidates include canna (shown), dahlia, elephant ears, gladiolus, calla lily and tuberous begonias. Learn how to dig — and store — tender bulbs over winter in six simple steps.
Step 1: Wait for Frost
Ideally, wait to dig roots until after the first frost. In warmer zones, dig after a hard frost blackens leaves. In coldest regions, start to dig bulbs as soon as you can, even after a light frost that just wilts leaves (shown above). Otherwise, if serious cold arrives early, this job becomes uncomfortably cold. Frost stops growing processes, which helps bulbs to dry quicker. But if your fall schedule is bursting at the seams, digging bulbs before frost is okay too. You'll likely have plenty of warmer days to help dry bulbs before storing.
Step 2: Cut Down Plants
Cut the plants down, leaving six inches of stem. This makes the digging process easier as you maneuver between plants. If you have a whole bed of plants to dig, like this canna row, cutting plants down is quickest if you use a sharp knife. An old kitchen knife works fine. Toss all leaves and stems into the compost pile. For monster tropicals like canna or elephant ear, cut thick stems into small pieces to speed decomposition. For amazing compost, layer this green compost component (tropical stems and leaves) with dry, mowed (chopped) autumn leaves.
Step 3: Dig Roots
Use a digging fork or shovel to pry the bulbs free from the soil. Start digging at the outer edges of plants to avoid spearing bulbs. Toss any nicked or damaged bulbs into the compost.
Step 4: Shake Off Soil
Shake the soil off the bulbs. If possible, try to tackle digging at a time before fall rains have soaked the soil. If not, shaking the soil from bulbs may not be effective. You may need to use your gloved hands to knock largest soil clumps off bulbs. If the weather is warm enough, it’s okay to hose off bulbs to help remove soil. Handle bulbs carefully, though. You don’t want to remove any outer protective layers.
Step 5: Trim Stems and Roots
Use hand pruners to shorten roots and stems. At most, leave a two-inch stem stub. Take care when cutting that you don’t nick bulbs.
Step 6: Dry Roots and Store
Before storing thick, moisture-laden bulbs like canna or elephant ears, it’s a good idea to dry the bulbs a bit. This helps to prevent rot during storage. Arrange them on screens or in mesh trays, and place them in a cool, dry place. Storing them in a shed or garage works well if temperatures aren’t hovering around freezing day and night. You can even arrange roots on a garden cart and wheel them outdoors on sunny days. After cut edges have sealed and the roots seem drier to the touch, pack them away for winter.
To store bulbs, pack in milled peat moss, perlite, shredded paper or sterilized dry (bagged) compost. Or store them in mesh bags, hung up or placed into boxes for winter. Add several sheets of paper between bulb layers to help absorb moisture and reduce chances of rot. For tender bulbs growing in pots, skip the digging and simply store bulbs as is—in soil, in pots. Cut off leaves and stems before storing.