Skip to content

Gladiolus: How to Grow Gladiolus Bulbs

It is the “Year of the Gladiolus,” a traditional perennial that is well-known for the long flower spikes and huge, multicolored flowers that it produces. Gladioli fare beautiful as cut flowers and look stunning when arranged in summer bouquets. The following is a guide for growing gladioli in your garden.

Gladiolus will be the flower of the year 2022

The National Gardening Bureau has designated 2018 as the “Year of the Gladiolus” for the gardening community. Plant some of these beautiful blooms in your yard this year as a way to celebrate their arrival.

There is a variety of gladiolus available for every kind of garden, from the small hybrids that are ideal for growing in pots to the larger-flowered Grandiflora hybrids that produce enormous spikes of flowers in an assortment of hues.


Gladiolus Flowers

Gladiolus

These attractive blooming plants, which belong to the iris family (Iridaceae) and are more generally referred to as “glads,” are available in a wide variety of colors and sizes. Gladioli normally grow to a height of between two and five feet and have flowers that vary in size from “miniature” blooms with a diameter of fewer than 3 inches to “giant” blooms with a diameter of more than 5 inches across.

It is common practice to position taller kinds, which need staking, at the rear of a garden in order to create an attractive contrast with shorter plants.

Give this summer bulb, which is more properly known as a corm, a second chance if your only prior experience with gladiolus plants consisted of a few stalks bending. When in full bloom, a mass of at least two dozen gladioli forms a garden sight of spikey blooms, with some of the flowers available for use in floral arrangements.

When to plant

  • Once the risk of frost has gone and the soil has warmed to at least 55 degrees Fahrenheit (13 degrees Celsius), you may begin planting gladiolus corms in the spring.
  • Plant a new round of corms about once every ten days starting from the date of the last frost until early June. Because of this, there will be blooms all the way to the beginning of September!
  • Gladiolus corms take anywhere from 60 to 90 days, depending on the type, to root, thrive, and bloom after being planted once the planting process has been completed.

Where to plant

  • Gladiolus may be grown in borders and flower beds, vegetable gardens, gardens dedicated to cut flowers, and even container gardens. 
  • To prevent the long flower stalks from being damaged by the wind, all that is required is a sunny position that is sheltered from it. 
  • Because they bloom in the late summer, when many other blooms have faded, they may be used to fill in voids and offer vertical beauty in a flower garden that is already established.

How to plant Gladiolus bulbs

Gladiolus

There is a wide range of sizes that may be found among gladiolus corms. If you want the best results possible, be sure to follow the instructions on the packaging. When planting corms, make sure the side with the smoother surface is facing down, and the pointy end should be facing up.

  • In order to get your garden ready, loosen the soil to a depth of around 12 to 15 inches with a garden fork or a tiller. After removing the soil, including a layer of compost or old manure that is two to four inches thick.
  • Planting corms with a diameter of at least 1 and 14 inches will result in flowers that are enormous in size.
  • Place the corm in the hole at a depth of about 4 inches, with the pointed end pointing upward. After covering it with earth, push down firmly.
  • Leave a distance of between 6 and 8 inches between each corm.
  • Plant your gladioli in rows if your primary goal is to harvest the blooms for bouquets. Taking care of the plants and gathering the blossoms is far less difficult.
  • For the greatest effect, plant the corms in groups of seven or more if you are going to combine them with other kinds of plants in borders or annual beds.
  • When planting the corms, make sure they get enough water.
  • Be careful to anchor any tall types that you plant when you first put them in the ground. When using the stakes, use extreme caution so as not to harm the corms.

How to grow Gladiolus bulbs

Put a layer of mulch that is two to four inches thick around your gladioli to help keep the soil wet and prevent weeds from growing.

During the summer, you should consistently water your plants if you only receive about an inch and a half of rain per week. If this is not possible, you should water them lightly while they are growing to keep the soil wet.

To maintain a steady supply of blooms, it is important to remove any flowers that have withered or died. When there are no more blooms left on a stalk, cut it off around two to three inches above the ground where it was growing.

Make sure the plant is not disturbed in any way so that it can reach maturity and produce corms for the following year.

How to overwinter

Protect your garden from the harsh winter weather by laying down a covering of hay or grass if you reside in USDA Hardiness Zone 8. Gladiolus bulbs may overwinter in the ground in areas that have milder winters, but only if the temperature does not drop below 28 degrees Fahrenheit on a regular basis.

Gladioli corms may be dug up in colder places (Zone 7 and below) after the foliage has died off and the first frost of the autumn season has occurred. The leaves will be killed by a mild frost, but the remainder of the plant will be unharmed. Be careful to remove the gladiolus corms from the ground before a severe freeze, since failure to do so may result in the plants’ death.


Gladiolus Care

Gladiolus care

Gladiolus bulbs produce trumpet-shaped blooms that open from the bottom to the top on a stalk that is fashioned like a sword. These flowers offer a sense of drama to the environment as well as bouquets. Because hybridizers have enlarged the color pallet, bearded irises are now one of the few flowers that can compete with it. 

True blue is not one of the colors that may be found in the happy flowerbed, despite the fact that some plant sellers attempt to convince customers otherwise by selling lavender plants with names like “Blue Moon.” The attractiveness of many contemporary cultivars is enhanced by the presence of wavy or frilled petal edges.

These plants are annuals, therefore their root systems are rather short, which results in a little present for the vertical accent they provide. Even container gardens on a balcony may make room for a dozen gladiolus corms to grow in the soil.

Move over, cosmos: blossoms of the gladiolus plant make wonderful partners for planting in vegetable gardens. The blooms entice pollinating insects, which in turn increases the output of tomatoes, and the vibrant colors of the blossoms ensure that they do not get hidden behind the rows of squash and beans. Gladiolus corms should be planted in the empty spaces left after spring vegetables such as peas and lettuce have been pulled out.

When they are not in bloom, gladioli have an odd appearance, but you can easily cover this phase by planting them in a flower garden. Another method is to put glads in the background of medium- to tall-growing plants, such as zinnias or dahlias, that will bloom after the glades have completed flowering.

Your glads may be kept off the ground by staking them with either half-round plant stake, single stem, or hoop stakes supports. The kind of support you choose will depend on the number of glads in your grouping.

Sunlight

Gladiolus are happiest when grown in full sun, but if that is not possible, they may still produce flowers when grown in moderate shade. Glads should be planted in areas that get full sun for the finest flowers about six to eight hours of sunlight per day.

Good soil

Gladiolus bulbs may be grown in almost any soil as long as it has good drainage. Even while glads may thrive in shallow planting, it is best to bury the seedlings at least 6 inches below the surface of the soil so that they can offer support to the growing branches.

Adequate water

After the first planting, be sure to water them well. The gladiolus should thereafter be watered once per week.

Whether conditions

If you plant your glads too early, you won’t be rewarded with flowers that are produced any sooner: When planted in chilly soil, gladioli will not bloom and may even decompose.

You should not plant your gladiolus bulbs until the temperature at night reaches at least 60 degrees Fahrenheit, and you should choose a location in your garden that gets at least five hours of direct sunlight each day.

From July up to the first frost, gladioli are in full flower. However, since the plants do not bloom continually, the flowering season may be prolonged by planting fresh corms about once every two weeks.

Feed them

Apply a liquid fertilizer with a balance of 10-10-10 components to the gladioli shoots that have just appeared.

Pruning

After they have wilted, dead flowers should be pinched back. If you want to dig up and store your bulbs, you should wait until the plant has finished flowering before cutting the blooms down to ground level using gardening shears.

Common Problems

Gladiolus plants might suffer damage from thrips at times. You may not be able to see the small flying insects, but you will see flecked foliage and browning at the ends of the leaves. Insect soap is an effective treatment for thrips.

Toxicity

Gladiolus corms are poisonous to humans and may cause gastrointestinal distress. It’s possible that animals and pets may develop lethargy, nausea, diarrhea, and excessive salivation. In the event that any of the pets in your care have ingested corms, please contact your veterinarian as soon as possible.


How to take flower cuttings

Gladiolus

  • Never cut the flower stems during the hottest part of the day; instead, do it very early in the morning or late at night.
  • When you go to the flower garden, carry a pail of warm water and a knife that is very sharp.
  • Remove the blooms off the stems when there are only one or two open buds. After being placed in a vase, the remaining buds will open and reveal their contents.
  • Using a diagonal cutting motion, remove the stalks from the bundle and drop them in the box.
  • If you wish to reuse the corms, be sure to keep at least four leaves on the plant when you put it in the ground.
  • Before you arrange the flowers in a vase, you should first let the bucket containing the flowers sit in a cool, dark spot for a few hours.
  • Take off any lower blooms that are beginning to wither, and trim about an inch from the base of each flower stem once every few days.

How to Store Gladiolus Bulbs

Gladiolus

Gladioli corms may be dug up in colder places (Zone 7 and below) after the foliage has died off and the first frost of the autumn season has occurred. The leaves will be killed by a mild frost, but the remainder of the plant will be unharmed. Be cautious to remove the gladiolus corms from the ground before temperatures drop below 28 degrees Fahrenheit, or the plants might be killed.

  • Dig around the entire plant with a spade, then grasp the crown of the plant and pull it up and out of the ground. 
  • When digging, take care not to crush or otherwise damage the corms. Remove any loose dirt by shaking the corms, but do not wash them. 
  • Discard any corms that have been injured. Reduce the height of the stalk so that it is 1 to 2 inches above the corm. If you so want, set aside some space in a separate container for the smaller cormels. If you transplant them every spring, you can expect them to bloom in two to three years.
  • If the weather is favorable, leave the corms out in the sun for one or two days to dry out. Remove any superfluous dirt before placing the corms in flats or trays made of wood. 
  • Cure in a warm and airy environment for a period of two weeks at a temperature of between 80 and 85 degrees Fahrenheit (27 and 29 degrees Celsius). Take out and dispose of the corms at the bottom that are the oldest from the base of the new plant.
  • It is not necessary to remove the husks that are on the corms.
  • To prevent difficulties with the disease, “bulb dust” containing a fungicide should be applied to the corms. Put the dust and the bulbs into the paper bag, and give it a good shake.
  • Keep the corms in bags made of paper or cotton, old onion sacks, or pantyhose for storage. Place the containers in a stack or suspend them from the ceiling so that air may flow between them. 
  • Keep the corms in a dry environment between 35 and 45 degrees Fahrenheit (2 and 7 degrees Celsius). A cool room is pretty ideal. Corms should not be allowed to get frozen.
  • If you want to enjoy these gorgeous blossoms again next year, be sure to replant the corms in the spring.

Gladiolus Types 

Gladiolus Types

There are many cultivars of glads, each of which is created from various variations of more than 250 species. The majority of these species are indigenous to southern and central Eurasia and Africa. You may discover these glads in garden stores and catalogs near you.

The following are the three primary happy groups:

Grandiflora: The most extensive classification of garden varieties. These cultivars are the most eye-catching of the group since their blooms may reach a width of up to six inches and they come in the widest variety of colors.

Nanus: Another category of plants that are often planted in gardens. Miniature hybrids that, in general, have a higher tolerance for the cold than their taller relatives. These are hardy up to Zone 5, and although they seem very similar to Grandifloras, they do not develop as many blooms. Because they rarely exceed a height of around two feet even when fully mature, they are an excellent choice for growing in containers or other confined areas.

Primulinus: Have daintier hooded flowers and very narrow leaves.


Some popular variety

  • ‘Prins Claus’: It has pink spots scattered over its white flower petals and has white blooms overall.
  • ‘Priscilla’: It blooms with flowers of a creamy white color with a yellow center and a pink rim.
  • ‘Dream’s End’: which, due to the fact that its flower spike may grow up to a height of three feet, is an excellent choice for use in the backdrop.
  • ‘Fun Time’: It blooms with golden flowers that are rimmed in crimson
  • ‘Green Time’: because of the distinctive lime-green color of its petals.
  • ‘Black Star’: It bears flowers that are rich purple-red.
  • ‘Candyman’: due to the exquisite, dark pink color of its blossoms.
  • ‘Costa’: It blooms with ruffled petals that have a blue-purple color.

FAQ

What does a gladiolus symbolize?

Gladioli are a symbol of moral fortitude, remembrance, loyalty, and integrity in one’s relationships. The gladiolus, which derives its name from the fact that it is designed to pierce the recipient’s heart, is also used to communicate infatuation. Using the traditional Victorian interpretations of the meanings of various flower colors, more meaning may be communicated via the use of color.

Does gladiolus come back every year?

Gladiolus flowers come in a vast range of hues and will continue to bloom year after year. In order to save their gladiolus plants from damage caused by subfreezing conditions, gardeners in the north will need to dig up the corms in the autumn and put them away for the winter. If a gladiolus did not bloom for whatever reason, it would be difficult to isolate the specific cause of the problem.

Do gladioli bulbs multiply?

Gladiolus, like many other types of perennial plants, produces new growth from a huge bulb each year, which then withers away and is replaced by new growth the following season. This “bulb” is really referred to as a corm, and each year the plant will develop a new one just on top of the old one.

Do gladiolus only bloom once?

Even though gladioli only open their petals once a year, the breathtaking display they provide more than makes up for the limited time they spend in bloom.