Cultivation

Gladioli are relatively easy to grow and as the corms are so inexpensive you can afford to use them as annuals, meaning you can experiment with different colours and styles from one year to the next. They can also be lifted before the first frosts, dried and stored until the following spring or mulched heavily in sheltered, free-draining areas.

There are risks to mulching in situ – corms could be damaged or even killed off in a very harsh winter – so be sure to cut the spikes down in autumn before the first touch of frost. You should also cover the clump with a plastic bin liner to keep the corms dry and mulch liberally with compost. In May, remove the plastic and spread the compost to act as a mulch to feed the emerging plants.

Although many suppliers suggest you can start planting out the corms in March and April, I recommend waiting until at least May when the soil has warmed and the chance of frosts faded. You can expect blooms from around 80 to 100 days after planting. If you are growing your gladioli as annuals for cutting, you should be able to squeeze in around 60 to 100 corms into a square metre, although don’t be tempted to plant all the corms at once. You can get a longer display by staggering your planting through May and June at fortnightly intervals.

Gladioli need reasonable soil to perform well but the key to abundant blooms is free-draining and well-prepared soil. Ensure the ground is free of weeds and plant the corms in groups at around 25cm deep. I usually remove a spade’s width and depth of soil and then arrange around five to seven corms at the base of the hole. By planting deeper, the corms get consistent moisture and temperature so the flowers need less staking.

Many of the gladioli featured here are the more compact dwarf types, and one of advantages of growing these is that they don’t require staking. The larger Grandifloras simply need four stakes in the corners of the clump and then string around the perimeter and a few pieces in between. Alternatively, pea sticks can be used but the main support is required at a metre off the ground.

To keep the spike looking fresh, both in the garden and vase, remove the lower flowers as they fade. When cutting gladioli, it is always best to remove the top bud, which often results in more flowers in the stem opening to their full potential. Stay vigilant for aphids and, if they appear, treat with an organic insecticide or environmentally friendly pesticide, such as SB Plant Invigorator – although gladioli are all reasonably trouble-free. They’re also extremely versatile and the sultry colours of the more modern hybrids make them excellent accent plants for airy perennials but can also complement stronger colours. The rich-red of Gladiolus ‘Flevo Flash’, for example, works wonderfully with Rudbeckia fulgida var. sullivantii ‘Goldsturm’ and Hylotelephium ‘Matrona’.