Overwintering Chocolate Cosmos -- Prepping Tubers for Storage, by PlantFunAndWhatnot on YouTube. 8 min 44 s.
- Video length
- 8 min 44 s
- Time to do it
- 30 minutes
- Difficulty
- Easy
- Steps
- 8
What you need
Steps
Lift the plants once frost has blackened the foliage or growth has died back naturally. The tubers are small, so dig wide with a fork and keep the root ball whole.
Do not shake all the soil off and store the tubers bare. Chocolate cosmos tubers shrivel quickly over winter because they are much smaller than dahlia tubers.
For the first method, tuck the cleaned tubers into lightly damp coir or peat moss. The mix should feel barely moist, like a wrung-out cloth, never wet.
For the second method, leave the root ball intact and knock off only the excess dirt. Store it bare in a box, or slip it back into its own pot.
Skip large pots. A big pot of soil holds a lot of moisture and dries slowly, so tubers left in it are more likely to rot over winter.
Store the tubers somewhere cool, dark and frost-free, around 5 to 10 degrees Celsius. A shed, garage or unheated spare room works well.
Check the tubers every few weeks. Mist the coir if it has dried out, and throw away any tuber that has gone soft, shrivelled or mouldy.
If you would rather not store tubers, keep one plant awake indoors over winter on a warm, bright windowsill and pot it on in spring.
Tips and common mistakes
Label each box with the variety and the date, because small tubers all look alike by spring.
Never let the coir sit soggy; damp, not wet, is the line between plump tubers and rot.
Wear gloves when digging and clean your fork between plants if you have had rot in the border.
Keep stored tubers away from warm rooms, which push them into early growth before spring light arrives.
Questions
Can I just leave chocolate cosmos in its pot outside over winter?
Only in a mild, frost-free climate. Elsewhere the soil in the pot stays cold and wet, and the small tubers usually rot or freeze.
When should I dig up chocolate cosmos tubers?
After the first frost has blackened the leaves, or once growth dies back in autumn. Lift them before hard freezes set in.
How do I wake the tubers up in spring?
Pot them into fresh compost in early spring, water lightly and keep them warm and bright. Shoots usually appear within a few weeks.
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.
