© Janet Davis

When the days grow cooler in autumn, it’s time to bundle up all those flamboyant summer-flowering bulbs, corms and tubers that hail from warmer climes and send them packing for the winter so you can enjoy them again next season.

ACIDANTHERA: Once the leaves of these sweet-scented plants have turned brown, dig the plants up and let them air-dry in a shady spot for a few days. Then remove all but two inches of the foliage, separate the offsets (young corms) and store in dry peat moss or perlite in a cool basement or garage.

AGAPANTHUS: Bring these container plants (best grown in pots since plants need to be rootbound to bloom well) with their tall starbursts of pale blue or white and strap-like leaves indoors before frost hits. Some experts suggest flowering suffers when stored too warm over winter, so choose a bright spot where temperatures stay cool. Leave the plant in its pot, stop fertilizing and water very occasionally.

BEGONIA: once we’ve had a frost that darkens and shrivels the leaves of these shade-lovers (the big flowered ones, not fibrous wax begonias which are treated as annuals), lift the tubers and bring them into a garage or cool basement room where they can dry. Remove leaves after a few days. If the stem doesn’t fall off on its own once dry, cut it back to about 1 inch. Store the tubers in a cardboard box filled with dry peat moss, sand or vermiculite. Cover the box with newspaper. Room temperature should be 5-10C (40-50F).

CANNA: After a light frost, cut off the withered leaves and stalk, leaving a few inches, then air-dry rhizomes in a sheltered spot for a few days. To prevent fungus, sprinkle them with powdered sulphur and store them in dry peat moss, vermiculite or perlite at about 15C (60F). In spring, divide the rhizome, making sure you have at least one planting “eye” on each division.

CROCOSMIA (MONTBRETIA): After the tops yellow, lift the corms, being careful to leave some soil around the roots since, like agapanthus, crocosmia don’t go dormant. Air-dry for a few days, cut back tops and place the corms and soil, several at a time, into pots of dry peat moss. Store at about 15C (60C).

DAHLIA: in their excellent book, Bulbs, Four Seasons of Beautiful Blooms (Storey Communications, 1994), Lewis and Nancy Hill recommended digging up the tubers before a frost – carefully, so you don’t damage them – shaking off the soil, then hanging the entire plant up in a garage or cool area to dry for a few days. Then cut off foliage to about 12 inches and continue drying. Finally, remove all but an inch of stalk and dust tubers with sulphur. If they are large, you can divide them, but each division should retain a bit of the “neck.” Label each tuber and store upside down in an airy box or basket, covered with sand, dry peat, vermiculite or perlite. Make sure they don’t dry out; moisten the packing material if necessary through winter. Store at 5-8C (40-45F) to prevent sprouting. (If frost has already touched your dahlias, follow this procedure anyway).

GLADIOLUS: After a light frost, lift the corms, leaving the leaves intact. Tie together the same colours, labelling them, then air-dry completely. Once dry, remove foliage and discard the old corms (which don’t flower again). Dust the new cormels with sulphur and store in a mesh or paper bag in cool spot.

Adapted from a column that appeared originally in the Toronto Sun

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