Gladiolus Bulbs

Do gladiolus bulbs come back every year?
Gladiolus are perennial, meaning they'll come back-if they're kept from freezing over the winter. Gladiolus bulbs need to be lifted and stored in zones lower than Zone 8. Most gladiolus bulbs aren't winter hardy, but they are reusable! And, glads are very easy to lift and replant. If you don't want to lift and store, try a hardy gladiolus variety.

Lifting and storing gladiolus is fairly simple, although curing them can take a few weeks. Here's how to lift and store gladiolus bulbs:

• In late summer, before the first frost, use a spade to dig up your gladiolus plants, taking care not to cut or damage the bulbs. The bulbs, or corms, will look much like they did when you planted them in spring, although they may have new tiny corms, called cormels, attached around the base. You'll be able to separate the older corms from the cormels after curing.
• Gently shake or brush off excess soil from the corms and store them in a well-ventilated area until the foliage is dry. Once dry, foliage can be removed for storing.
• Set your gladiolus corms in a box or tray lined with paper or parchment. Leave plenty of space between the bulbs to allow for air flow, and leave your corms uncovered. Set them in a dry, well-ventilated area for two to three weeks.
• Once your corms are thoroughly dry, remove and discard the last year's dried up corms, located at the base of the new corms. Be sure to toss out any corms that look mushy or rotted. Separate the new small corms found around the base of the existing corms, and save those to re-plant, too!
• Place your gladiolus corms in paper or mesh bags, or in fresh newspaper, and they're ready to store. Storage temperatures should be 35 to 45 degrees Fahrenheit.

In spring, you can replant your gladiolus in much the same method used to plant them the first time. They'll happily come back year after year.

Can I leave gladiolus bulbs in the ground?
What happens if you don't lift and store your tender gladiolus? Well, many forgetful gardeners have been surprised to find glads come back after a hard frost spent under the ground. Some gladiolus are hardier than others, and dwarf glads are particularly hardy. And, of course, there are species bred specifically to be hardy. For most glads, however, the safest option is to lift. Or, try gardening with hardy gladiolus and save yourself the work!

What month do you plant gladiolus bulbs?
The right time for planting gladiolus bulbs varies by zone, but gladiolus should be planted after the threat of frost has passed and the soil has warmed to over 50 degrees Fahrenheit. Glads can be planted any time in spring, for Zones 8, 9, and 10. In Zones 5, 6, and 7, gladiolus should be planted in April. In Zones 3 and 4, gladiolus should be planted in May. Again, it's all about the last frost date, so don't rush to get these in the ground and be burnt by frost!

Some gardeners like to stagger their gladiolus plantings, to ensure that they bloom all season long. You can try this method by planting some of your glads at the final frost date for your zone, planting more two weeks later, and planting even more two weeks after that. The staggered bloom time ensures that you'll have lots of blooms through the summer months. Another way to achieve a staggered effect? Simply plant gladiolus with early, mid, and late bloom times.

How many years do gladiolus bulbs last?
Because gladiolus form new corms over old ones, you're actually planting new bulbs every year-and your glads will last for as long as you care for them. For most glads, that care involves lifting and storing in winter. Bulbs won't last indefinitely out of the ground, so you'll need to replant your glads within the year that you lifted them.

Will gladiolus bulbs multiply?
Gladiolus bulbs do multiply, forming new child cormels around the original corm. If you're gardening in a warm climate, or using hardy glads, you'll find that your gladiolus grow bigger and more plentiful each year. If you live where you can leave your glads in the ground year round, you may need to lift and divide them after several seasons. If you're lifting and storing each year, you can separate the cormels from the parent, replanting them in the spring to enlarge their presence in your garden.