Dahlia Tubers: How to Lift, Divide and Store Them Over Winter, by The Garden Clinic on YouTube. 10 min 2 s.
- Video length
- 10 min 2 s
- Time to do it
- 45 minutes
- Difficulty
- Easy
- Steps
- 9
What you need
Steps
Wait until the first frost blackens the leaves, then cut the stems back to about 10 cm above the ground. In mild areas lift once flowering has finished.
Push a garden fork into the soil about 30 cm out from the stem and lever the whole clump up. Work around all sides so you do not spear the tubers.
Shake off the loose soil and rinse the clump with a hose so you can see every tuber clearly. Trim off any broken roots.
Check each tuber. Cut away any that are soft, mushy, black or chewed by insects, and wipe your blade before moving to the next plant.
Find the eyes, which are small pale buds clustered on the crown where the old stem joins the tubers. A tuber with no eye will not grow.
Cut the clump into pieces with secateurs or a knife, keeping a short piece of the old stem attached to each one. Each piece needs at least one eye and one fat tuber.
Label each variety as you go, then leave the pieces in a dry, airy, frost-free spot for a day or two so the cut faces callus over.
Pack the tubers stem end up in a box of dry potting mix, sawdust or vermiculite, leaving a little space between them. Store in a dark, frost-free place.
Check the box every few weeks over winter. Throw out anything shrivelled or rotten, and pot up any tubers that shoot early after a warm spell.
Tips and common mistakes
The eyes sit only on the crown near the old stem, so a clean tuber snapped off without stem will never sprout.
Never store tubers damp or in sealed plastic, as trapped moisture is the main cause of rot over winter.
Wear gloves and cut away from your body when dividing, and lift heavy clumps with your legs, not your back.
Divide only every three or four years if you want the biggest flowers, since crowded clumps produce fewer blooms.
Questions
Do I have to dig up dahlias every year?
No. Leave them in the ground for three or four years in mild climates. Lift them yearly only where the soil freezes hard or stays wet through winter.
How can I tell a healthy tuber from a rotten one?
Healthy tubers are firm and plump. Rotten ones feel soft and squashy, look black or mouldy, and should go straight in the bin, not the compost.
When do I plant the stored tubers out again?
Plant them in early spring once the soil has warmed and frosts have passed, or start them in pots indoors a few weeks earlier.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
