Whether these plants need lifting at all depends on how cold winter gets where you garden. The guidance here applies to climates where soil freezes or temperatures regularly drop below what these plants tolerate, not to regions with mild winters (N.C. Cooperative Extension, about 3 years ago).

Five plants show up in this guide, each with its own kind of storage structure: gladiolus (corm), dahlia (tuberous root), tuberous begonia (tuber), caladium (tuber, grown mainly for its foliage rather than its flowers), and calla lily (rhizome) (UW–Madison Extension, Chippewa County, about 4 months ago).

N.C. Cooperative Extension counts dahlias, calla lilies, gladiolus, and caladiums among the tender bulbs with especially low winter survival outdoors, and Oregon State University Extension places tuberous begonias in that same non-hardy group (N.C. Cooperative Extension, about 3 years ago; Oregon State University Extension, reviewed last year).

All five follow the same broad arc: lift, cure, store. But the timing and handling differ enough from plant to plant that treating them identically is where mistakes happen, which is why the next two sections split into a shared workflow first, then plant-specific detail.

Timing is a balancing act. Dig too early and the plant hasn't had time to store enough energy to fuel next year's growth; wait too long and cold or frozen soil can damage the storage structure before it ever reaches the shed (Illinois Extension, roughly 11 months ago).

The signal to watch is the foliage, not the forecast. Once leaves have yellowed, browned, or died back, or within a few days after the first frost blackens them, it's time to lift. Waiting longer invites the organisms that cause rot (Illinois Extension, roughly 11 months ago; N.C. Cooperative Extension, about 3 years ago).

Tuberous begonias are the exception. Bring them in before a hard frost hits rather than after, removing the whole pot from outdoors while the root ball and soil are still intact (Oregon State University Extension, reviewed last year).

None of this maps to a fixed date. Track the first-frost forecast for the specific area, since timing shifts by region and even by yard, and let the plant's own signs, not a page on the calendar, set the schedule.

Four steps apply to all five plants. The details that vary by species come next.

1. Cut back and lift. Once foliage has died back or blackened, cut the top growth down and dig the storage structure out of the soil. Dig carefully to avoid bruising or slicing into it (N.C. Cooperative Extension, about 3 years ago).

2. Cure before storing. Nearly all of these need a drying period in a shaded, well-ventilated spot around 60 to 70°F before they go into a container. How long that takes varies a lot by plant, from a day or two up to three weeks, and turning the pieces periodically during this stage helps them dry evenly on all sides (Illinois Extension, roughly 11 months ago; N.C. Cooperative Extension, about 3 years ago).

3. Inspect, and skip division for now. Check each piece for soft spots, disease, or insect damage, and toss anything compromised. Resist the urge to divide dahlia clumps or split other structures at this stage; that job goes better in spring, right before replanting (Illinois Extension, roughly 11 months ago).

4. Pack in a ventilated container. Layer the cured pieces two to three inches deep in peat moss, sand, vermiculite, sawdust, or coconut coir, inside something with airflow. A cardboard box or milk crate works well; an airtight bin does not. Keep pieces from touching each other (Illinois Extension, roughly 11 months ago; N.C. Cooperative Extension, about 3 years ago).

Label everything before it disappears into storage. A University of Minnesota Extension guide, revised in 1998, notes that plenty of prized plants have been lost simply because nobody wrote down what was in the box. For large clumps, write the name on more than one piece, since a piece can break off in storage and end up sitting there unlabeled on its own (University of Minnesota Extension).

Storage temperature is where these five plants actually diverge. Each has its own target, which is why it gets a dedicated breakdown instead of one number for the whole group.

The table below compares cure time and target temperature for each plant (Illinois Extension, roughly 11 months ago).

Gladiolus needs the longest cure and the coldest storage of the five. After the two-to-three-week dry-down, snap off the small cormels that form around the base of the original corm, then remove and discard that old corm entirely; what's left is the new corm that flowers next year (University of Minnesota Extension). Choose a storage spot that won't freeze; an unheated garage works fine for the roughly 40°F target as long as temperatures inside stay above freezing (Illinois Extension, roughly 11 months ago; N.C. Cooperative Extension, about 3 years ago).

Dahlias are the fastest to prep on this list. Figuring out how to store dahlia tubers for winter comes down to patience with the digging, not the drying: a day or two of curing is enough before they go straight into the packing medium (Illinois Extension, roughly 11 months ago).

To store calla lily and caladium bulbs indoors, follow the same cure-and-pack routine outlined above, just at different temperatures. Both cure for one to three weeks, but calla lily rhizomes want a cool spot around 50°F, while caladium tubers have a listed target closer to 60°F, warmer than any of the other four plants here (Illinois Extension, roughly 11 months ago). Neither needs special treatment beyond that: pack them whole in the layered medium from the workflow section, and give them a separate labeled box if they're sharing shelf space with a plant that needs a different temperature.

Tuberous begonias follow their own sequence entirely. Lift the whole pot before a hard frost, soil and all, and let it cure for several weeks in a dry, cool spot such as a garage or basement. After that, shake off the soil and remove any remaining stalks and roots, since leftover plant material left on the tuber can rot and spread decay into it. Place the bare tubers on screen trays, or pack them in dry peat, sawdust, sand, or another insulating material, and store them in a dark, cool location just above freezing (Oregon State University Extension, reviewed last year).

A growing-season habit affects storage odds here too. Begonias are especially prone to overwatering, and a tuber that goes into fall already waterlogged tends to store poorly (Oregon State University Extension, reviewed last year).

Whatever the plant, check stored material periodically through winter and pull out anything that's rotting before it spreads to its neighbors (Illinois Extension, roughly 11 months ago; University of Minnesota Extension). If the packing medium feels bone-dry and pieces have started to shrivel, mist it lightly with a spray bottle. If it's gone too damp instead, pull the affected pieces out, let them air-dry, and repack rather than leaving them sitting in moisture (N.C. Cooperative Extension, about 3 years ago).

Come late winter, check the storage boxes again for anything that's shriveled or started to rot, and clear out whatever didn't make it (Illinois Extension, roughly 11 months ago).

Division waits until spring too. Dahlia clumps in particular are easier to split right before planting than they were back in fall (Illinois Extension, roughly 11 months ago). Once the last frost has passed, most of these plants can go straight back into the ground, or get started indoors ahead of that date for earlier blooms (N.C. Cooperative Extension, about 3 years ago; Illinois Extension, roughly 11 months ago).

Tuberous begonias need a bit more coaxing before they go back outside. Set the stored tubers on damp potting soil in a warm spot; once roots and shoots appear, pot them into rich, well-drained soil, then move them to a shady spot outdoors after the last frost has passed (Oregon State University Extension, reviewed last year).

By the time the ground has warmed enough to plant again, the only real decision left is where in the garden each one goes back in.