The magnificent flower stalks of the gladiolus look like swords, which gave the plant the Latin name gladiolus (sword flower). Gladiolus are true sun worshipers and thrive best in full sun perennial beds. If you properly care for the onion plant, which has become very popular again in recent years, it will be extremely robust and less susceptible to diseases and pests.
How should gladioli care be?
Gladiolus need a lot of sun, regular watering without waterlogging, fertilization every 4 and 8 weeks, thinning after flowering and overwintering in a frost-free room. Pests such as thrips can be controlled with insecticide solutions.
How much water does the gladiolus need?
Gladiolus are quite thirsty and need to be watered regularly, especially on hot summer days. The following applies:
- Water whenever the top few inches of soil feel dry. This may be necessary twice a day on hot days.
- Avoid waterlogging as this causes the onions to rot quickly.
- So loosen heavy soils with a little sand when planting.
- Mulch the soil so that the moisture does not evaporate so quickly.
When is fertilization done?
If you have already enriched the garden soil with some compost or manure when planting the gladiolus, it is sufficient to fertilize the plants for the first time four weeks later. A second fertilizer application takes place after eight weeks. Use commercially available long-term flowering fertilizer (€11.00 at Amazon). This contains all the nutrients that the gladiolus needs for he althy growth and abundance of flowers.
How to cut?
As soon as the flower stalk has completely bloomed, the withered parts are shortened down to the base of the leaves. Be sure to only cut back the green of the gladiolus completely when the leaves have yellowed significantly and become unsightly. This allows the onion to continue to grow and stores important nutrients for the next year.
If you cut gladioli for the vase, you should always leave three or more petals on the bulb. If the stem is cut directly above the ground, for example because you need the full length for a vase, the bulb plant may die.
How are gladioli overwintered?
Gladiolus are not hardy and must be kept indoors over the winter. In autumn the tubers are dug up and stored well dried in a cool but frost-free room.
What pests and diseases can affect the plant
Newly bred gladiolus varieties are often attacked by thrips. These pest insects, also known as bubble-footed or fringe-winged insects, are between one and three millimeters in size and feed on plant juices. This damages the gladiolus so badly that it can wither.
You can recognize the infestation by the silvery stripes along the leaves and flowers. Since the pests migrate to the tubers via the outer bracts to overwinter, the Federal Association of German Gardeners advises cutting off the affected gladioli close to the ground. The onion usually sprouts again he althy afterwards.
If your gladioli are repeatedly attacked by animals, you can place the bulbs in an insecticide solution that is effective against the pests before planting.
Tip
For large-flowered gladioli, it is advisable to support them so that the flower stalks do not break. Special bamboo or plant poles, which are hardly noticeable due to their natural coloring, are well suited.
