Gladioli grow from corms, which are underground storage organs much like bulbs. ... Gladiolus come in a riot of colors and will re-bloom every year. Northern gardeners will need to lift the corms in fall and store them through the cold season to protect the gladiolus from freezing temperatures.

Can gladiolus be left in the ground over winter?

In warmer regions, gladiolus can remain in the ground through winter, provided a hard freeze (28°F or colder) isn't common in your area. In colder regions (Zone 7 or colder), dig up gladioli corms once the foliage has faded after the first fall frost. A light frost will kill the foliage, but not the rest of plant.

Can you leave gladiolus bulbs in the ground all year?

No one will deny that it's simply the best way to keep them alive and well. Even so, if you leave them in the ground, it just might happen that your gladioli survive the winter to bloom again. They can even persist that way for many years.