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Tall or small, grow cheery gladiolus and learn how to overwinter the bulbs

Tall gladiolus flower stems with blooms in blue, peach and pink sway in a garden.
Orest Lyzhechka
Gladiolus make great cut flowers for adding to vases and container arrangements. They look beautiful in the landscape, too. Learn when, where and how to plant them, plus how to store the bulbs or "corms" for overwintering.

"Glads" are tall, showy perennials and are part of the iris family. Their tall stems flower with multiple blooms along the stalk and come in many colors and heights.

Gladiolus are perennial flowers in the iris family that grow from a bulb, or "corm." These are favorites in a garden setting or grown along borders.

The taller types can grow up to 4 feet and are great as cut flowers. When you're buying the bulbs, choose from a range of hues, from white to orange, yellow and red, down to the deepest burgundy. Each fall, you'll need to dig up those corms and overwinter them, then replant again in spring.

Certain types of gladiolus don't require you to dig up the bulbs, though. The shorter dwarf varieties grow about 2 feet tall. One variety, the "Abyssinian" gladiolus, grows more like a Siberian iris, blossoming as a white flower with a burgundy throat. Another shorter type, called "Atom," is hardy to Zone 5 and has brilliant red flowers with white edges. The corms of these two types can stay in the ground and overwinter.

When, how and where to plant gladiolus

  • The time to plant gladiolus is now!
  • Find a sunny spot with well-drained soil and plant them about 6 inches deep.
  • Stake them to keep the stalks upright and straight.
  • If you're growing them in a garden, group five to six corms together in a clump so they can support each other.

How to store the corms over the winter

  • In the fall and after a frost, dig the corms up.
  • Peel off the old corm and leave the new one.
  • Let them dry for a few days, then store the corms in an onion bag and leave in a cool basement for the fall and winter. Next year, replant the corms.

Harvesting gladiolus to use as cut flowers

  • Cut the flowers stalks early in the morning or at night, but forego the heat of the day.
  • Cut flower stalks diagonally using a sharp knife and place the stems in a bucket of lukewarm water.
  • Look for stalks that have just one or two open blooms; the buds on the stalks will open after you put them in water.
  • After harvesting stalks to use in bouquets and arrangements, leave them in the water bucket in a cool, dark place for a few hours.
  • Remove any faded flowers, then cut an inch off the bottom stalk every day or two to keep them looking fresh.

A question about soggy raised beds

Q: Given all the rain we have had in May, even my raised beds are soggy. What can I do to get the beds ready for planting? Can I add a peat mix to the raised beds? - Celeste, via email

A: If your beds have good water drainage, they should dry out pretty quickly. If they're not drying out, there are better things to add other than peat moss.

Peat moss will actually absorb that moisture and hold it there, so it will stay soggy. Instead, try potting soil with perlite added or try the coconut husk fiber known as coir.

A question about when to plant hyacinth bulbs

Q: I just received about 100 English wood hyacinth bulbs from my mother’s garden. I trimmed the dead and dying leaves off and the roots are dry. Is it safe to plant them now? Or should I wait until fall? - Laurel, in Chilson, NY

A: It sounds like the bulbs have gone dormant. You could put them in the ground now, or you can hold them in a dark basement, where they'll stay dry and cool. Then, once fall comes, go ahead and plant them like you would any other spring-flowering bulb.

All Things Gardening is powered by you, our audience! Send us your toughest conundrums and join the fun. Email your question to or better yet, leave a voicemail with your gardening question so we can use your voice on the air! Call Vermont Public at 1-800-639-2192.

Listen to All Things Gardening Sunday mornings at 9:35 a.m., and subscribe to the podcast to listen any time.

Charlie Nardozzi is a nationally recognized garden writer, radio and TV show host, consultant, and speaker. Charlie is the host of All Things Gardening on Sunday mornings at 9:35 during Weekend Edition on Vermont Public. Charlie is a guest on Vermont Public's Vermont Edition during the growing season. He also offers garden tips on local television and is a frequent guest on national programs.
Mary Williams Engisch is a local host on All Things Considered.