How Tall Do Gladiolus Get

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Last Updated on January 12, 2022 by Cristina

The vividly colored elegant flowers spread out on the lofty stem are guaranteed to take your breath away – but how tall do gladiolus get? The inflorescence of gladiolus is what draws everyone’s attention, whether it is in a flower display or the garden. When grown in full sun, the flowers have a striking color that’s hard to replicate.

But raising gladiolus is not an easy task. They grow taller than your average house plant and need support. Read along before you purchase your spring corms.

Gladiolus Flower

The name gladiolus comes from the Latin word gladius, meaning sword. You’ll often find people referring to gladiolus as sword lilies due to their shape.

They’re a summer perennial that grows from corms. The corms are responsible for the size and appearance of the flower. Big, healthy corms produce tall, impressive gladiolus.

Gladiolus thrive in warmer climates as perennials. You can grow them in colder climates too. But if you live in a zone that experiences hard freeze, you need to dig out and store the corms inside each fall.

Gladiolus Flower

The flowers come in various colors, but the intensity depends on how much sun they’re getting. The size of the blooms varies from 3 to 5 inches in diameter.

Read more about How Much Sun Do Morning Glories Need

How To Grow Tall Gladiolus

The good news is you can plant gladiolus in pots and in-ground. Gladiolus originates from Africa, thus it grows best in USDA Hardiness Zones 7 to 10. If you live in a colder climate, growing them in pots is better. This way, you can keep them in your garden during summer and bring them inside after the first frost.

Thoroughly inspect the corms before buying for any signs of mold or softness. If you’re planting in pots, pick smaller bulbs or larger ones for in-ground sowing.


Plant the corms in spring after the last frost has passed. The soil’s temperature needs to reach 55°F before planting. Gladiolus need 2 to 3 months to root, grow and bloom. If you want to have blooming gladiolus all summer long, plant new corms every 10 to 14 days, from March to May.

Some hardy varieties like Gladiolus Communis can withstand temperatures down to 14°F.


Gladioli don’t need overly rich and hard soil. They will grow best in mildly fertile and well-draining soil. A water-soaked ground can lead the corms to rot before they even develop. When planting in pots, choose containers with several drainage holes.

Work in compost into the soil, digging 12 to 15 inches right before planting. Add sand or gravel to boost drainage, if you’re working with particularly hard soil.

Gladiolus Soil


Gladiolus has a moderate need for water. If you have them in the ground, and you get less than an inch of rain weekly, water regularly. It’s essential to keep the soil moist when the gladioli are blooming. You can use mulch around the plant to help it retain moisture during summer.

Gladioli in pots benefit more from soaking instead of watering. Soak the container once a week for best results. Remember that well-draining soil is essential; otherwise, it will retain water and deteriorate the plant.

Gladioli Height: How Tall Can They Grow?

Gladiolus can grow 2 to 5 feet tall in optimal conditions. There are over 260 species, so you can find shorter and taller exemplars. The commonly grown gladiolus are significantly taller than other garden flowers, so it’s best to plant them near a fence or wall.

  • Yellowstone – grows up to 5 feet with blooms that last for a month.
  • Alaska – grows up to 4 feet and can attract hummingbirds and butterflies to your garden.
  • Impressive – a miniature gladiolus that features truly impressive flowers and grows up to 2 feet.
  • Blue Moon – grows at least 5 feet tall and has giant breathtaking flowers.

When To Fertilize Tall Gladiolus

Gladiolus need fertilizing 2 to 3 times during the season. First, add compost or manure to the ground before planting the corms. If you don’t have any, go for slow-release plant food.

Then, when the plant reaches 10 inches, add liquid, water-soluble fertilizer. Finally, when the flowers start developing, it’s time for the third dose of fertilizer.

Remember that gladiolus doesn’t need overly rich soil; therefore, adding food 3 times per season is enough.

AeroGarden Liquid Nutrients (1 Liter)


Gladioli As Cut Flowers

Gladioli make perfect cut flowers, whether alone or when combined with other flowers. Cut the gladiolus when only a few flowers on the flowering stalk have opened. The rest will open while in the vase.

Prepare a pail with warm water and get a sharp knife or garden scissors to cut correctly. Cut in the am or at night, but not at midday when the weather is sizzling.

Cut diagonally, but not too low – you want to leave a few leaves so the corm can continue to feed. Leave the cut flowers in a cool and dark area for a few hours before arranging them.

Check Out How To Make Potpourri From Roses: Easy Tutorial

How To Stake Gladioli

You can’t control the outdoor weather, so it’s better to be safe than sorry. Provide support for the tall stems before the wind catches a chance to bend or even snap them.

Use a PVC pipe, wood cuttings, fallen branches, bamboo stalks, or other material. It needs to be as long as the gladiolus expected growth plus 10-12 inches.

Install it close to the plant’s root, but beware not to hurt the corm. Push the stake 10 inches into the ground. Use jute to tie the plant to the stake. Tie it every few inches for optimal support.

If you’ve planted the gladioli in rows, put a stake at each end of the row. Then tie a garden twine to connect each of the stakes supporting the plants from the front and back.

Do preventative staking instead of remedial after the plant has tumbled.

Final Say – How Tall Do Gladiolus Get

Gladiolus are elegant plants with colorful flowers that make perfect cut flowers. They can grow anywhere from 2 to over feet tall, depending on the type. It’s crucial to stake them to prevent breaking once the plant is fully developed.

Gladioli grow from corms in warm climates and thrive in full sun. They need 70 to 90 days to develop fully, and the flowers can last up to 4 weeks.

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