Most summer flowering bulbs should be dug and stored when the leaves on the plants turn yellow. Use a spading fork to lift the bulbs from the ground.
Leave the soil on achimenes, begonia, canna, caladium, dahlia and ismene bulbs, but wash other varieties. Store these bulbs in clumps on a slightly moistened layer of peat moss or sawdust in a cool place.
Separate your bulbs by species or variety and spread the washed bulbs in a shaded place to dry. Inspect your bulbs for signs of disease and keep only large, healthy bulbs that are firm and free of spots. Discard any undersized bulbs.
Once the bulbs have dried, store them away from sunlight in a cool, dry basement, cellar, garage or shed at 60 to 65 degrees. Avoid temperatures below 50 degrees or above 70 degrees unless different instructions are given for a particular bulb.
Try to keep the humidity in the storage area as low as possible, and never store bulbs in an area where ethylene gas produced by fruit is present.
Large numbers of bulbs can be stored in a container with peat moss, sand, perlite or vermiculite. If you have only a few, you can keep them in a very loose knit sack or paper bag and hang them by string in a sheltered, cool area.
Be sure that air can circulate around your stored bulbs. Deep piles of bulbs generate heat and decay, so never store bulbs more than two or three layers deep.