Gladiolus grow from tender structures similar to bulbs, called corms. The plants produce tall spikes that are adorned with multiple blossoms during the summer months, but they die back in the fall and go dormant for winter. In areas where the ground freezes, the corms must be dug up and stored indoors until the weather warms up in spring. Gladiolus requires only minimal pruning, primarily in the fall as you prepare the plants for winter.
Pinch off the old flowers on each stem as they wilt and die off. Grasp the withered bloom behind flower and break it off flush with the stalk.
Cut off the entire stem at the base once all the flower buds have finished flowering. Dispose of the old flower stalk after removal.
Prune back the foliage to within 2 inches of the soil once it yellows and dies back naturally in fall, usually after the first frost. Dig up the corms after foliage removal.
Spread the corms out in a warm, well-ventilated room to dry for three weeks. Pull the remaining foliage off the corms once they are completely dried. Store in paper bags in a dry 40- to 45-degree-Fahrenheit location until spring.