Q. When & how should I divide my canna bulbs?
Tender bulbs and tubers must be removed from the soil in fall and cleaned off. Let them dry, and shake off as much soil as you can without damaging the plant material. Cut off any remaining stems about one inch above the bulb. Place them in a container with dry vermiculite and lightly cover them. Dampen the vermiculite and check monthly. If dry, lightly dampen the material. The container should be stored in a cool dry dark place until March when the container can be moved into more light.
To get a jump on the warm weather in mid-April, the bulbs, etc. can be planted in a pot just big enough to hold them and covered lightly. Use a peat mix. Put them in a light place that is warm during the day. If they get leggy, some, like begonias, can be pinched back. When the warm weather arrives, gradually introduce them to the outdoors and after a week or so, the plants can be put into the soil.
For more information, see this eBook
As a member of PHS, you can access this book by clicking on the above link and logging in with your PHS membership number. That is the number that is on your membership card. Contact email@example.com if you are having problems logging into our eBook system.