Store dahlia tubers for winter.

1. Decide whether to lift

In a cold or persistently wet winter, lifting gives tender dahlias a protected resting place. Leaving them outdoors is a calculated option in a mild climate with freely draining ground; an unusually harsh or wet winter can still cause losses. A hardiness-zone number alone does not describe drainage or an exposed pot.

Use local autumn weather, not a fixed October deadline. Once top growth has died back or frost has killed it, prepare to lift before the soil freezes. Keep labels with their plants. See the first-frost checklist for other plants needing attention.

2. Lift the whole clump gently

Cut stems shortly before digging, rather than leaving open, hollow stems to collect rain. Loosen soil all around the plant and lift underneath the clump. Pulling on the stem can break the narrow connections between tubers and crown.

Remove soil carefully and reject soft, rotting material. For this beginner route, keep sound clumps together and postpone division until spring. Drain moisture from the cut stems and dry the clumps in an airy, sheltered place out of direct sun. Surface drying is the aim; do not leave roots exposed until they become brittle.

3. Pack for moisture balance

Choose a storage method matched to your room. UNH describes cured tubers packed in slightly moistened vermiculite, sand or wood shavings, while RHS describes dry insulating materials. Neither method means packing wet tubers away or allowing condensation to accumulate.

• Cool: keep above freezing and below 50°F (10°C); check with a thermometer.
• Labelled: name each clump and add the storage date.
• Accessible: use a box you can open and inspect.
• Protected: verify that a garage or shed really remains frost-free.

4. Check through winter

Inspect about monthly and after severe cold. Remove rotting tubers promptly. If the packing is damp or condensation appears, correct excess moisture and airflow; if roots progressively shrivel, review how much moisture the container loses. Do not pour water over the whole box to fix one dry clump.

Record what changed so the next check has a comparison. Storage cannot guarantee every tuber survives, and some cultivars keep better than others. In spring, inspect the crown and buds before dividing; the dahlia growing guide covers the next planting stage.