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How & When To Plant Gladioli Bulbs What You Need To Know!

red gladiolus

Gladiolus flowers are tall and towering, making for a bold and show-stopping centerpiece to any garden or flower arrangement. With their striking architectural structure and wide range of colors, gladioli make perfect garden borders and vase pieces. While buying these amazing blooms might bring some instant satisfaction, nothing quite beats being able to go into your backyard or garden and cut beautifully bright flowers you grew yourself.

Gladioli are an amazing choice to mix into your flower garden when your perennials are still reaching maturity. Gladioli are relatively easy to grow, and they make excellent cutting flowers. With very little work needed when compared to other bulbs, gladiolus flowers burst into bloom during the summer and decorate your garden with delightfully tall and colorful flowers. But how do you plant and grow gladiolus flowers in your own garden?

garden flower divider

About Gladiolus Flowers

Gladiolus flowers are a genus of perennial plants (perennials can be regrown each spring) in the iris family. These tall, striking beauties are bulbous plants but don’t grow from a bulb. Instead, gladiolus flowers come from corms, a bulb’s closely related cousin.

The tall, spikey orchid-like blooms are sometimes called sword lilies due to their long, blade-like appearance. The flowering plants usually end up between 2 and 5 feet tall with flowers that can range from less than 3 inches to more than 5 inches across. The distinct narrow blade, or sword shape, of their deep green leaves gives them their name.

Gladiolus flowers come in such a wide variety that you are bound to find the perfect type for your garden vision. There are around 300 species of gladioli, ranging from flowers with plain petals to frilly and or ruffled petals. The floral displays come in every color: red, purple, pink, orange, yellow, white, and even multi-colored petals.

Depending on the species used to create the gladiolus hybrid, the blooms can take on three distinct shapes.

Gadiolus hybrid shapes:
  • Gladiolus Grandiflora: Large, funnel-shaped flowers that can have up to 30 blooms on one tall spike
  • Gladiolus Primulinus: Hooded flowers with ruffled petals and contrasting colors
  • Gladiolus Nanus: Small, hooded flowers with lance-shaped leaves

Most gladiolus hybrids come from these three parent species, but each type makes for a stunning floral arrangement.

Planting Gladiolus Flowers

Gladiolus flowers are versatile. You can plant them in your garden, raised flower beds, or large containers. For your gladioli plants to produce the best blooms, they need to be planted in full sun. While you can plant gladioli bulbs in shady areas, the colors will be less vibrant overall. They need 6–8 hours of direct sunlight per day to achieve the ultimate vibrancy.

When planting gladioli, you will need to loosen your soil, rake out the rocks and other debris, and try to add compost or manure. While not necessary, compost and manure will enrich the soil and improve the soil’s water retention, permeability, drainage, and aeration. Gladioli have the best performance in soil that is well-drained.

Lastly, depending on the size of the bulb, you need to space your bulbs 6–10 inches apart in your garden. If you have larger bulbs, they will need to be planted deeper into your soil, but on average, your gladioli bulbs should be about 2 to 6 inches deep.

Planting Gladiolus
Image Credit: Nowaja, Pixabay

When To Plant Gladioli Bulbs

Even if you have the perfect soil, you need to know when to plant gladioli bulbs. Gladioli are summer flowering plants; therefore, they need to be planted in warmer weather to give them the best bang for their buck.

You should only plant gladioli bulbs in the spring after the frost has passed and your soil has warmed up to around 55°F (13°C). If you want continuous blooming flowers through summer and early fall, you will want to plant your bulbs every 10 days to rotate their growth cycle. Depending on the variety of gladiolus you choose to plant, you’ll have flowered blooms within 60 to 90 days.

How To Plant Gladioli Bulbs

If you want to add your gladiolus flowers to your backyard garden or flower beds, you can follow these steps:

Steps for planting in the garden:
  • Dig a hole that’s 15 inches in diameter. Add compost or fertilizer.
  • Place the bulb about 4 inches deep with the pointed end facing the surface.
  • Cover the bulb with soil and press it firmly into the ground.
  • Make sure to space your bulbs 6 to 8 inches apart in your garden or flower bed.
  • If you are growing gladiolus bulbs specifically to cut flowers, make sure to plant them in rows as it is easier to tend to the plants and harvest.
  • If planting taller varieties of gladioli, make sure to stake your bulbs so they can grow to their proper height.
  • Water the bulbs thoroughly during planting.
leveling soil with rake
Image Credit: terimakasih0, Pixabay

How To Plant Gladioli Bulbs in a Pot or Container

If you want to plant your flowers in a specific pot or container rather than in the flower bed or garden, here are a few steps you need to take:

Steps for planting in a pot:
  • Always remember that some types of gladioli bulbs will grow very tall, so keep that in mind when planning which container or pot to use.
  • Ensure your pot or container has good drainage. Your bulb won’t grow if you keep it in soggy, dense soil.
  • When adding your bulbs, make sure they are spaced 4–5 inches apart, with the shoot facing upwards.
  • Plant the bulbs twice the depth of the actual bulb.
  • Cover your bulbs with compost, water them, and place them somewhere sunny.
  • Make sure to water two to three times a week at a minimum, so the bulbs don’t try out in the direct sunlight.
woman hands putting soil in the pot
Image Credit: rolkadd, Shutterstock

Growing and Cutting Gladiolus Flowers

Once your flowers are planted, you may be wondering how to keep them healthy and growing throughout the season.

Make sure to do the following:
  • Remove the dead or faded flowers from the stalks to keep your gladioli blooming. If all the flowers on the stalk are gone, cut the stalk 2 to 3 inches above the soil so it can regrow.
  • Only cut your gladioli flowers with one or two open blooms; the rest of the blooms will open once inside of your vase or container.
  • Cut the flower stalks in the early morning or late evening, and avoid the most intense heat of the day. Gladioli flowers enjoy sunlight, not baking to death.
  • Use a sharp knife to avoid damaging the stalk.
  • Cut diagonally through the stalks and place them in a bucket of lukewarm water.
  • Place the bucket of flower stalks in a cool, dark place for a couple of hours before arranging the flowers in your vase or container.
  • Make sure to remove the fading or dead flowers at the lower ends of the stalk.
  • Cut around 1 inch off the bottom of each flower stalk every few days to leave room for growth in your vase.
Image Credit: Alexei_other, Pixabay

Some of Our Favorite Gladioli Varieties

Since gladiolus flowers come in such a wide variety, we wanted to share some of our personal favorites with you. The size and color variations produce creative flower displays and beautifully unique flower gardens.

The jester variety offers ruffled petals with deep red centers, and the black beauty gladiolus has large, deep maroon petals. If you’re after some lighter colors, the white prosperity gladioli produce snow-white blossoms, and the pastel mix creates a pretty contrast of pink, white, yellow, and peach.

If you want something more adventurous, you can also go for the parrot mix, which produces contrasting color petals with different colored throats. No matter what you pick, there is a color and petal-type just for you.

garden flower divider

Fun Facts about Gladiolous Flowers

  • Gladiolus flowers are one of the August birth flowers, along with the brightly colored poppy.
  • Some species of the gladiolus flowers can cause skin irritations or allergic reactions when touched.
  • The word gladiolus comes from the Latin word “gladius,” meaning sword.
  • British and Mediterranean gladiolus plants were modified for medicinal purposes; the stem base was used to extract thorns and as a bandage!
  • Gladioli symbolizes remembrance, faithfulness, and honor.
  • Even though gladiolus flowers are perennials, they technically use corms instead of a bulb, but the words have similar meanings.

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Featured Image Credit: Capri23auto, Pixabay


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