Everything You Need To Know About Growing Gladiolus

Written by Joel SImon in Perennials

Gladiolus produces multiple booms that are available in a variety of colors that makes this perennial a favorite among gardeners

Gladiolus are perennials that are native mainly to South Africa but they are also found in Eastern Africa, Northeastern Africa, the Mediterranean area, and the Arabian Peninsula with about 250 varieties including hybrids.

They have showy sword-like blooms that are a great option for flower arrangements.

Sword lilies as they are also known are bulbous plants meaning the plant and roots grow from the bulb.

Plants use their bulbs to store energy for times of drought when the plant can no longer sustain the foliage and dies off or during the winter months.

Bulbous plants require a little more careful attention because if they are overwatered or in an area that doesn’t drain well then they won’t survive and will suffer from root rot quickly.

PLANTING GLADIOLUS

Gladiolus are best planted in hardiness zones 5 through 10 in well-drained soil.

If the hardiness zone you live in is lower than 5 you can treat them as an annual and collect the seeds for the next season.

They are best planted 2 to 3 inches apart in rows and the rows are about 6 inches apart and 3 to 6 inches deep depending on the size of the bulb.

It is recommended to soak the bulb for at least 24 hours before planting to help the bulb to sprout.

They prefer a soil pH range between 6.0 through 6.5.

If your gladiolus is going to be sprouted from seed then it is suggested to use a cardboard seed starting container and start them 3 to 4 weeks before the last frost.

For best results, it is recommended to till some compost into the soil before planting which is known as amending the soil.

Amending the soil will provide nutrients and help the soil retain water which will help during the hot summer months.

For a longer blooming time, it is recommended to continue to plant new bulbs every two weeks until the beginning of July.

This will give you different blooming times that will give you blooms all season long.

GLADIOLUS USES

Gladiolus will do well in flower gardens, cottage gardens, shade gardens, raised garden beds, and potted containers, and they are also used in flower arrangements.

FERTILIZING AND WATERING

Gladiolus need to be fertilized when they get to about 10 inches tall and again when the blooms start to show color. They should be fertilized with a balanced liquid fertilizer or with homemade liquid fertilizer.

When applying fertilizer, it is best to apply it between the base of the plant to the tips of the branches. This area of the plant is known as the drip line.

They prefer well water soil with about one inch per week or until the top two inches of soil are moist. More water will be needed during times of drought or if they are growing in a raised garden bed.

MULCHING

Mulching gladiolus will help the soil retain water which will reduce the amount of time it takes to water them.

The thickness bed of the mulch is best between 2 to 3 inches thick and may need to be reduced if you live in a moist and rainy climate or if you are is getting more rain the usual.

To keep the bulbs from rotting, the mulch may need to be removed altogether.

The mulch will also help with weed control which is important because they don’t compete well with weeds.

It is best to add new mulch every year as the older mulch breaks down.

BLOOMS

Gladiolus Blooms

Their stalks of blooms are often used in arrangements as cut flowers which are harvested in the morning after the lower three blooms have opened.

Their blooms come in two varieties, the first is a trumpet-shaped bloom that forms on a thick stalk while the second variety is a single star-shaped bloom that forms on a thin stalk.

Gladiolus blooms attract bees and flies with long tongues to get the nectar as well as hummingbirds.

When the blooms become wilted, removing them will cause the gladiolus to rebloom, this is called deadheading.

When this is done the blooms can’t produce seeds therefore the plant will rebloom to produce seeds or bulbs.

PROPAGATING

Gladiolus grows from a bulb that is also known as a corm. Each bulb will produce baby bulbs that will in turn sprout new plants.

You can dig them up, separate the bulbs, and replant them to help fill in an area which is much faster than starting them from seed.

Their blooms will produce seeds that can be sown the following season or sprouted indoors 3 to 4 weeks before the last frost.

Using seeds to grow your gladiolus will take a few years to fill in an area.

Every 3 or 4 years it will need to be divided by carefully digging the plant up with a spade or small shovel and gently separating the root ball into two.

PESTS

Gladiolus has many pests therefore having plenty of organic and natural pesticides is a must to stop the damage they can cause as well as the viruses they may be carrying.

  • Thrips
  • Nematodes
  • Aphids
  • Slugs
  • Snails
  • Caterpillars
  • Cutworms
  • Bulb mites
  • Mealybugs
  • Plant bugs or capsid bugs
  • Spider mites

DISEASES

Gladiolus can grow into a thick mass of foliage that can become an issue if the humidity and heat are high enough for a long enough period.

Some of these issues can be prevented with a baking soda spray or essential oil spray, or they need to be thinned to allow for proper airflow.

  • Stemphylium leaf spot
  • Curvularia leaf spot
  • Botrytis blight
  • Scab
  • Stromatinia dry rot
  • Fusarium yellows

VIRUSES

Plant viruses are caused by pests causing damage to a plant, therefore good pest management is a must.

  • Bean yellow mosaic
  • Cucumber mosaic
  • Tomato ringspot
  • Tobacco ringspot

OVERWINTERING

When the leaves of the gladiolus turn yellow they should be removed at ground level and the bulbs can be removed from the soil.

In a hardiness zone of six or less, the bulbs should be removed from the soil and stored indoors during the fall because they are not hardy enough to make it through the winter temperatures.

In hardiness zone seven and lower, the bulbs can be left in the soil after the leaves have been cut back.

In mid to late November they should be covered with a layer of mulch that is about 4 to 6 inches thick to provide some extra insulation during the cold winter months.

VARIETIES

Gladiolus are available with ruffled and double blooms that come in different colors including bi-colored blooms.

They are also hybrid varieties available that were bred for their booms and colder climates.

PURPLE FLORA GLADIOLUS

  • Plant size – grows to about 5 feet tall and 6 inches wide
  • Drought tolerant – no
  • Sun requirements – full to partial sun
  • Blooming colors – 3 to 4 inches wide dark purple ruffled blooms that form on a spike in mid-summer until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – purple flora sword lily

VUELTA GLADIOLUS

  • Plant size – grows to about 5 feet tall and 6 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – red blooms that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – vuelta sword lily

JESTER GLADIOLUS

Jester gladiolus is a hybrid variety with bicolored blooms.

  • Plant size – grows to about 4 feet tall and 5 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – yellow ruffled blooms with a red on one or two of the lower petals that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – jester sword lily

WHITE PROSPERITY GLADIOLUS

  • Plant size – grows to about feet tall and inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – white trumpet-shaped blooms that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – white prosperity sword lily

PRINCE OF ORANGE GLADIOLUS

  • Plant size – grows to about 5 feet tall and 5 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – orange trumpet-shaped blooms that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – prince of orange sword lily

CHARMING LADY GLADIOLUS

  • Plant size – grows to about 3 feet tall and 5 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – light pink trumpet-shaped blooms that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – charming lady sword lily

AFTERSHOCK GLADIOLUS

  • Plant size – grows to about 5 feet tall and 5 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – bright pink trumpet-shaped ruffled blooms that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – aftershock sword lily

BLACK STAR GLADIOLUS

  • Plant size – grows to about 5 feet tall and 5 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – dark red trumpet-shaped blooms that form on a spike in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – black star sword lily

ABYSSINIAN GLADIOLUS

  • Plant size – grows to about 3 feet tall and 5 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – white star-shaped blooms with a purple star in the center that droop down and appear in June until the first frost
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – prince of orange sword lily

PRISCILLA GLADIOLUS

  • Plant size – grows to about 5 feet tall and 6 inches wide
  • Sun requirements – full
  • Drought tolerant – no
  • Blooming colors – white with pink on the edges of the petals
  • Foliage – long narrow green leaves
  • Deer resistant – yes
  • Also known as – priscilla sword lily

Joel SImon

As a kid, Joel found enjoyment in caring for the many houseplants he grew up with, learning how to transplant them safely, cloning them, and more. At about the age of 10, he wanted to see if he could sprout an orange seed from a store-bought orange and ended up using it as a science experiment in a school project. Throughout the many years of gardening, he has helped many friends and family set up their food and botanical gardens. After years of caring for plants, he was talking with other gardeners and discovering old methods of farming and botanical gardening. Joel has decided to share his knowledge for others to enjoy as he has for many years.

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