Before the snow flies—and certainly before the ground is likely to freeze—dig up tender summer bulbs which otherwise will perish if left in the ground over the winter.
What is a tender bulb?
Summertime bulbs, tubers and corms, such as canna lilies, gladiolus, begonias, caladiums and freesia, will not successfully overwinter in our gardens throughout most of Canada’s hardiness zones. (Hardy bulbs you can leave in the ground or plant now include crocus, tulips, daffodils and scilla.)
But, when do you dig them up? And, how do you ensure bulbs don’t rot or freeze when stored indoors?
Digging up (lifting) bulbs
Tender bulbs are ready to lift when the plant has died back after the first frost, well before the ground freezes. Dig them out gently so as not to damage them. Trim the stalk leaving on about 2 cm. Why? If you cut too close to the bulb, you might cut or otherwise expose next year’s growing tip to the air. This allows an entry point for mildew. Handle with care!
Tip: Use a garden fork when digging. A spade can slice through a bulb and destroy it.
Brush off clumps of soil from bulbs. With gladiolus, note there may be lots of little round babies attached to the mother; or, you may find some corms have twinned. In either instance, don’t crack them apart. Discard wizened bulbs.
Tip: Avoid washing bulbs. This introduces moisture. When it comes to storing bulbs, it’s all about keeping them clean and dry.
Leave the bulbs to air out in a cool, dry location on wire mesh or on something that allows maximum air circulation. Store like this for 10 days or so, ensuring the bulbs are dry and don’t freeze. The bulbs must be dry before storage. Otherwise, they can rot.
Tip: I use a large plastic bread tray (recycled from a landfill). Spread bulbs which will still have damp soil clinging to them and allow to air dry.
Tip: Watch out for mice and squirrels which will eat them.