In some places, gladiolus can be left in the ground all winter. In colder climates, however, they would freeze and die. Gladiolus can be saved, though, if placed in the root cellar and replanted in the spring. Here’s how.
First, gently dig the entire gladiolus plant and place on newspapers in a shady spot that won’t get frosted. A porch is ideal. Let them sit there for a week or two until the stems easily pull away from the corms.
Next, separate the new corms from the old ones.
Often, a gladiolus will form two new corms where the old one was. With some wood chips and a bucket, place these new corms on top of the chips not touching one another.
Cover with more wood chips. Continue until the bucket is full. Place more chips on top, cover and place in the root cellar for the winter. In the spring, begin planting the gladiolus about ten days before the last frost. Planting ten or twelve at a time is ideal. Continue planting them every ten to fourteen days until they are all in the ground. This will assure a timely presentation of flowers throughout the summer months.