By Charlie Nardozzi
A frost has occurred in many parts of the country, and it’s time to dig and store your tender bulbs such as dahlias and gladiolus. In all but the warmest areas of the country, dahlias and gladiolus will not survive the winter outdoors in the ground. 
Whether they’re grown in containers or the garden, these bulbs need to be protected in a warm location for winter. Let’s look at each bulb and its requirements for winter care.
- Dahlias: Dahlias are hardy in the ground in USDA Zones 8-10. In Zone 7, they may survive if mulched heavily with bark mulch in late fall to keep the ground from freezing. In colder areas, cut back the foliage after a frost to 2 to 4 inches from the soil line. Carefully dig out the tubers with a shovel or iron fork, and store them in a dry, warm, well-ventilated garage or basement, out of direct sunlight, to dry. Once the tubers are dry, carefully remove the soil and leave about a 1-inch-long stem with each tuber. Move the tubers to a 45 to 55 degree F dark basement or room, and store the tubers in a ventilated box or basket filled with slightly moistened peat moss or sand. Check the tubers periodically through the winter, and mist them if the skins start to shrivel. If any tubers start to rot, remove them so they don’t infect the other tubers.
- Gladiolus: Most gladiolus are only hardy to USDA Zone 7. A few are hardy to Zone 5. For winter, dig gladiolus corms after frost has killed the foliage and it turns brown. Loosen the soil with a shovel, being carefully not to damage the corms. Pull them out by the dried tops, and store them in a warm (85 degree F) garage, shed, or room, out of direct sunlight, to dry. After about two weeks, when the corms are dry, cut off the tops to within 1 inch of the corm, remove any excess soil, and remove the old bottom corm. Save the newer top corm for planting next year. To store, place the corms in single layers in a slotted box with newspaper between the layers, or store them in old onion bags. This will allow the air to continue to circulate around the gladiolus corms while they are being stored. Keep the corm box in a dark, cool, dry location that ideally stays around 40 degrees F.