Gladiolus Growing Zones

Geography

• Generally speaking, gladiolas are grown outdoors year-round in U.S. Department of Agriculture plant hardiness zones 8 through 11. These areas sustain winter temperatures no colder than 10 degrees Fahrenheit and the soil never freezes deeper than 3 inches.

Considerations

• Gladiolas may still be grown in cold winter regions, but as a seasonal summer plant. Once danger of frost passes in spring, corms are planted. Two to four months later, they produce attractive flowers. After fall frost kills the leaves, the corms are dug up and overwintered indoors in a cool, dry location.

Expert Insight

• Since these plants are susceptible to corm rot and gray mold, it's important to let corms dry for 2 to 3 weeks after lifting them from the garden. Cut off the dead leaves and stems and then dip the corm in a fungicide before storing.