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Gladioli corm division: how to do it and when to split Gladioli

#1 · 18th October 2022, 4:24 am

I'm fairly new to gardening so don't know a lot about it. I noticed this year that we had a pretty poor showing of our gladioli compared to last two years. I was told that's because they might be congested and I need to dig them up and seperate them and store them over winter. I hadn't a clue how to do this so watched a load of utube vids and set to. So far I've dug up 41 corms and am curing them (only about 50 more to go!)

The thing is quite a few of them are co-joined twins and even triplets, by which I mean I can see the old corm on the bottom, and two/three healthy looking (I think!) bulbs on top. What do I do with these twins/triplets? Do I leave them joined when I've removed the old corm, or do I need to seperate them? I'm worried that if I try to seperate them I might damage all the new corms. I really don't know what to do. I tried googling my question in several different ways but am none the wiser. Surely I can't be the only gardener with twin/triplet gladioli!!! That's why I've joined this forum hoping to find an answer to my question.

#2 · 19th October 2022, 2:03 pm

Quote from Lee Garden Ninja on 19th October 2022, 2:03 pm
Hi Sandy,

Thanks for the question about how and when to split Gladioli or Sword Lillies as they are sometimes known.

Gladioli grow from corms which can often look like bulbs. A Corm is a vertical underground stem and storage organ whereas a bulb is an underground stem with fleshy and scale-like layers surrounding a central bud. The base of the bulb is made up of a cluster of adventitious roots. I often this of corms as small hard nuggets and bulbs as onions when identifying them but Gladioli are a bit of a trickster!

Gladiolus look a bit like a bulb but are really just a large scaly corm. To grow Gladioli these corms get buried and then send up growth above soil level each year to produce a flower of some description.

When to split Gladioli?

Aim to divide and split gladioli corms every 3-4 years. To stop them from becoming unproductive and congested. Lift and divide then in late summer after they have finished flowering.

How to split Gladioli?

Dig with a garden fork around clump of Gladioli in Autumn after they have finished flowering. Dig beneath the corms as not to damage them, usually 6-8 inches.

Lift the clump up with the fork releasing it from the ground, You may hear a crack or ripping noise as the smaller roots snap or release from the soil.

Now cut back all foliage to 2-3inches with clean sharp secateurs.

Brush off the soil and then 'cure' the Gladioli by placing them in the sun, a bit like onions, until they dry. This makes them easier to split without damage.

Once dry aim to tease them corms part in your hands, a bit like breaking bread. Aim to get single bulbs, if you have twins then leave them in tact as they are not developed enough to survive on their own at this stage. The main part is to remove the older crusty corm from twins or triplet corms.

Compost and dispose of old wrinkly or crusty corms - ie the parent corm.

Plant either in autumn or in spring after the frosts. I prefer to plant them in autumn so they don't rot or get nibbled in the shed.

https://youtu.be/Dv3mhh1eFFc

Where to plant Gladioli?

Gladioli need full sun and simply won't produce decent flowers, if any when planted in shade. As they come from warm sunny climates such as South America or the Mediterranean. They require good drainage! So not great for wet clay or heavy shade. Plant in pots and move to a sunny spot if this is your garden aspect!

Should I feed Gladioli?

During flowering, it's important to feed Gladioli so they can save up enough energy in the corm for next yeards flowers or to propagate by producing new corms. The best feed is either tomato liquid feed or liquid comfrey tea. Dilute accordingly and water this in during flowering until the flowers fade.

https://youtu.be/drHhi8PQyQg

I hope that helps answer the question Sandy!

Happy planting.

Lee

Hi Sandy,

Thanks for the question about how and when to split Gladioli or Sword Lillies as they are sometimes known.

Gladioli grow from corms which can often look like bulbs. A Corm is a vertical underground stem and storage organ whereas a bulb is an underground stem with fleshy and scale-like layers surrounding a central bud. The base of the bulb is made up of a cluster of adventitious roots. I often this of corms as small hard nuggets and bulbs as onions when identifying them but Gladioli are a bit of a trickster!

Gladiolus look a bit like a bulb but are really just a large scaly corm. To grow Gladioli these corms get buried and then send up growth above soil level each year to produce a flower of some description.

When to split Gladioli?

Aim to divide and split gladioli corms every 3-4 years. To stop them from becoming unproductive and congested. Lift and divide then in late summer after they have finished flowering.

How to split Gladioli?

Dig with a garden fork around clump of Gladioli in Autumn after they have finished flowering. Dig beneath the corms as not to damage them, usually 6-8 inches.
Lift the clump up with the fork releasing it from the ground, You may hear a crack or ripping noise as the smaller roots snap or release from the soil.
Now cut back all foliage to 2-3inches with clean sharp secateurs.
Brush off the soil and then 'cure' the Gladioli by placing them in the sun, a bit like onions, until they dry. This makes them easier to split without damage.
Once dry aim to tease them corms part in your hands, a bit like breaking bread. Aim to get single bulbs, if you have twins then leave them in tact as they are not developed enough to survive on their own at this stage. The main part is to remove the older crusty corm from twins or triplet corms.
Compost and dispose of old wrinkly or crusty corms - ie the parent corm.
Plant either in autumn or in spring after the frosts. I prefer to plant them in autumn so they don't rot or get nibbled in the shed.

Where to plant Gladioli?

Gladioli need full sun and simply won't produce decent flowers, if any when planted in shade. As they come from warm sunny climates such as South America or the Mediterranean. They require good drainage! So not great for wet clay or heavy shade. Plant in pots and move to a sunny spot if this is your garden aspect!

Should I feed Gladioli?

During flowering, it's important to feed Gladioli so they can save up enough energy in the corm for next yeards flowers or to propagate by producing new corms. The best feed is either tomato liquid feed or liquid comfrey tea. Dilute accordingly and water this in during flowering until the flowers fade.