Gladiolus are a popular choice among flower-growers, not least because their trumpet-shaped flowers come in a wide variety of colours. They are part of the lily family and derive their name from the Latin for sword because of their sword-shaped leaves. They grow from bulbs perennially and as a result don’t need a great amount of care. However, for them to grow at their best and produce more and larger flowers, deadheading should be carried out after they flower. In the UK this is usually in late July or August.
Watch for when the trumpet-shaped flowers start to wilt and dry. This is the time to start deadheading, unless you want to wait for them to seed. This will provide you with an opportunity to increase your gladiolus crop, but it will deprive the plant of an extra energy boost that would otherwise help increase plant and flower growth. You could even cut whole stems with their flowers on just before they bloom and put them in a vase inside. If you do this, cut them at a 45 degree angle. Otherwise, move on to step two.
Take your secateurs or shears and snip the dead flowers off where they meet the stem. If seeds have already started to form, cup your hand under the flowers as you snip them off. You can then collect them or discard them.
Only once all the flowers on one stem have died and been removed should you snip the stem right down to where it emerges from the leaves at the bottom. Your gladiolus should then bloom even stronger next year, providing you with another attractive display for your garden and home.