Answer: Glads are not terribly hardy and do not need a winter cold treatment. So, some might survive to bloom, but there's a better chance if you dig them.
The foliage needs to keep growing as long as possible to replenish the bulbs so they can bloom again next year. In the fall the corms should be dug up for winter storage. Clean them and cut off the tops. Dry them for a week or two in a cool (35-40 degrees), dark, dry, frostproof area. When completely dry, store them in paper bags (not plastic) in a well ventilated cool dry area. They will be ready for planting in the spring. One tip - try not to plant Gladioli in the same spot for several years in a row. A new location every year helps to assure a healthy and vigorous crop. Thanks for writing!
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