Overwintering Tubers and Bulbs
Many tender plants — such as Dahlias, Begonias, Cannas, and Gladioli — grow from tubers, rhizomes, or bulbs that can’t survive freezing temperatures.
To keep them healthy for the following year, you’ll need to lift, dry, and store them safely through the winter.
Step-by-Step Guide
1. Wait for the First Frost
Let your plants keep growing until the first light frost blackens their leaves — this signals that the plant’s energy has moved back down into the tuber or bulb.
Avoid digging them up too early, as they need that time to store food for next year’s growth.
2. Cut Back the Top Growth
Once frost has damaged the foliage:
Cut stems down to about 10–15 cm (4–6 in) above the soil.
Leave the tubers or bulbs in the ground for a day or two (if the weather is dry) to allow the sap to retreat into the roots.
3. Lift the Tubers or Bulbs Carefully
Use a garden fork or hand fork to gently lift the clump from underneath.
Shake off most of the loose soil — don’t wash them, as moisture can encourage rot.
Handle gently to avoid bruising.
4. Dry Them Out (Cure Them)
Spread the lifted tubers or bulbs on newspaper or trays in a dry, frost-free, airy place — like a garage, shed, or greenhouse bench.
Leave them for 7–10 days to dry and toughen their skins.
For Dahlias, remove any remaining foliage once they’re dry, and gently brush off the rest of the soil.
5. Pack for Winter Storage
Once dry, place them in boxes or crates filled with:
Dry compost,
Peat-free potting mix, or
Wood shavings or sand
Make sure they are not touching each other, and label each variety.
Store in a cool (5–10 °C), dark, and frost-free place — such as a garage, cellar, or shed.
6. Check Occasionally Through Winter
Every few weeks, inspect your stored tubers and bulbs:
Remove any that show signs of rot or mould.
If they look shrivelled, lightly mist the storage medium with water.
This small bit of maintenance helps ensure you’ll have strong, healthy plants to replant in spring.
7. Replant in Spring
When frosts have passed and the soil starts to warm:
Pot up the tubers or bulbs indoors from late March to April to get them started early.
Plant them outdoors from mid to late May once all danger of frost has passed.
Water well and feed regularly for a strong display later in the year.
🪴 Extra Tips! 🪴
Label everything clearly before storing — it’s easy to forget which tuber is which!
Don’t seal the containers completely; allow airflow to prevent mould.
If space is tight, smaller bulbs like Gladioli or Begonias can be kept in paper bags or mesh trays.
In very mild areas, Dahlias and Cannas can sometimes be left in the ground if the soil is well-drained — but cover heavily with mulch for insulation.