They’re easy, colourful and make great cut flowers. The Gladiolus is, in many ways, like the summer tulip and they are no more difficult to grow. Like tulips, they make perfect, long-lasting cut flowers. Of course, tulips go in during the autumn and gladioli corms are planted in the spring. But, like all good garden bulbs, if you get them in the ground they will flower.
There are over 260 species of gladioli and even more varieties. Here are some tips for growing them in your garden.
How to grow Gladioli
All gladioli are easy to grow.
- As soon as the soil has warmed up in March or April, plant the corms 20cm (8in) deep; this is deeper than most books will tell you, but if they are secured deep in the ground you are less likely to need a stake.
- Plant them about 15cm (6in) apart.
- If you have bought quite a few, don’t plant them all at once. Stagger their planting and you will get a better succession of flowers.
- Gladioli need plenty of water to flower well.
So, if you can, dig a trench and pile well-rotted manure into the base before planting. This will help feed the bulbs and will also retain water.
On well-drained poorer soil, extra watering will be required.
- As soon as the flowers appear and until at least three weeks after flowering, apply a high-potash feed every two weeks.
- Lift them for the winter when the leaves turn yellow-brown and snap the corms from the stems. Dust with sulphur and dry them out for a couple of weeks. Then snap the new corms from the old, discarding the old and keep them dry and cold (but frost-free) until they are replanted.
You can dig and divide the clumps every few years to select the best corms for replanting. Without this, the new cormlets forming will invade the space of the original corm and the nutrients will have to be shared. The risk is lots of foliage and no flower spikes.