How to Grow Gladiolus
Gladiolus At a Glance
Difficulty
Easy
Category
Flower
Sun Exposure
Full Sun
Frost Tolerance
Frost Tender
Cold Hardiness
Survives to -7°C
Plant Family
Iridaceae
Growing Season
Warm Season
Plant Lifecycle
Perennial
How to Start It
★ Recommended for beginners
Gladiolus corms (flat, round bulbs) cannot take frost, so plant them about 1 week after your last frost. Set them pointed side up, 12 cm deep and 15 cm apart, in full sun. Plant a few more every 1 to 2 weeks until early summer for flowers over a much longer stretch.
Gladiolus grow tall spikes of flowers that last about a week in a vase. Frost kills the corms, so in most of Canada you dig them up in fall, store them indoors and plant them again each spring.
When To Start
Gladiolus needs warmth. Wait until your last frost has passed and the soil has warmed before sowing.
We do not have exact sowing dates for this one yet.
When should you plant Gladiolus?
Your planting dates depend on your local climate. Sign up and add your location to unlock personalized dates.
Your Gladiolus Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
Your Gladiolus Calendar
Set your location to turn these into exact dates and reminders.
Plant gladiolus corms 12 cm deep, more every 1 to 2 weeks
1 week after your last frost· every year
Cut gladiolus spikes when the lowest flowers open
80 days after your last frost· every year· optional
Dig up gladiolus corms, dry them and store them frost free
3 days after your first frost· every year· optional
Water your new gladiolus plants well while they settle in. Deep and slow is best.
About 1 days after you plant it
Your gladiolus corms should be waking up. Keep the soil moist, but never soggy.
About 30 days after you plant it
Exciting time! Tall gladiolus can tip over, so give each stem a stake to lean on.
About 90 days after you plant it
The Journey Ahead
Gladiolus's Lifecycle
Seedling
Mature Plant
Seed Production
Step 1
Prepare Your Space
12 cm
Seeding Depth
15 cm
Plant Spacing
30 cm
Row Spacing
Vertical Growing
No.
Succession Planting
Yes: plant corms every 1 to 2 weeks in spring for a long season.
Good Companions
Bad Companions
Step 2
Planting & Sprouting
Growing Tips
- 1Grow gladiolus in full sun for strong, straight spikes.
- 2Mix compost into loose, well-drained soil before planting, since the corms rot in soggy ground.
- 3Water deeply once a week, and feed with compost tea when the flower spikes appear.
- 4Push a stake in at planting time and tie tall types to it, so wind and rain do not knock them over.
- 5Tiny insects called thrips leave silvery streaks on leaves and flowers, so spray them off with water and remove damaged flowers.
- 6Gladiolus corms are toxic to pets, so keep dogs from digging them up.
Seedling Phase
Step 3
Growth & Maturity
120 cm
Mature Height
15 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
When to Pick
Blooms mid-late summer; a classic long-lasting cut flower
How to Harvest
- 1For a vase, cut a spike when the lowest 1 to 3 flowers have opened, and the rest open over the next days.
- 2Leave at least 4 leaves on the plant so the corm can build up strength for next year.
- 3After the first fall frost, or once the leaves turn yellow, dig up the corms and cut the stems off 2 to 3 cm above them.
- 4Let them dry in an airy spot for about 2 weeks, then snap off the old shrivelled corm underneath and keep the new one.
- 5Store the corms in a paper bag or open box in a cool, dry place that never freezes until spring.
Step 5
Saving Seeds
Seed Production
Still have a question?
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