Over Wintering Tender Bulbs and Tubers

Overwintering bulbs will save you money and may result in larger plants next year… I have used this method successfully for over 20 years — Britta Johnson

Overwintering tender bulbs and tubers can preserve special varieties and save money. These tips are intended for fall storage of begonias, canna lilies, dahlias, gladiolas and other tender bulbs.

  •  Tag special colours or varieties with ribbon or tape before blooms finish
  • After foliage is frozen down, dig up bulbs and tubers. Cut foliage close to top of bulb and clean off as much dirt as possible
  • Separate varieties (using tags if kept from time of purchase)
  • Lay bulbs and tubers on newspaper in trays and leave in a dry cool place for 3-7 days. The basement is great for this.
  • Clean off all dirt (a chopstick works well with canna tubers), and remove the last of the foliage. Some people dust the bulbs and tubers with Bulb Dust before storing but I never have.
  • Keep colours or special varieties labelled separately in mesh onion bags
  • Use cardboard boxes or plastic tubs with lids (keep begonias, glads, and cannas separate)
  • Coarse vermiculite is the best packing material (perlite or fine vermiculite gets quite dusty)
  • Pour a layer of vermiculite in the base of tub, arrange a layer of bulbs, add another layer of vermiculite, another layer of bulbs, etc. topping up with vermiculite
  • If using mesh bags make sure the vermiculite gets around the bulbs
  • Close containers and store in cold room or slightly heated garage
  • If you don’t have a cold room, store in a basement closet close to an outside wall. Do NOT store on garage floor as frost and moisture can still come up from the bottom. Set tubs on pallet, boards or bench instead of the floor.

In The Spring

  • Pot up begonias in mid to late March, providing light once shoots are showing
  • Pot up cannas between the end of March and the middle of April. Any sooner and they will be too tall and flimsy by the time you can plant them out. I wait until mid April and they still get to 5-6 ft tall and bloom in Aug.
  • Plant cannas in a straight sided or V-shaped pot to allow for fall removal as the tubers will completely fill the pot.
Written by Britta Johnson. Pictures supplied by Britta Johnson.