Classification, origin and description
Common name: Gladiolo, Monachetta
Typology: Perennials, Bulbose
Propagation: division of the bulbs
Etymology: the name of the genus comes from the Latin gladiolus = small sword and indicates the spadiform leaves.
The genus includes almost 300 species widespread between Central Europe, the Mediterranean basin and tropical and southern Africa. Of these, over a hundred come from the Cape region. However, it is not the pure forms that are grown, but the hybrids that are very numerous and cover practically the whole range of basic colors and shades: white, yellow, orange, red, violet, two-tone. Gladioli are plants from 60 cm to 1.2 m tall; the dark green leaves are thin and pointed at the ends; the robust flower stem bears an apical, one-sided spike inflorescence. Each flower is made up of 6 tepals: 1 central higher, 3 lower folded back and 2 lateral, located behind the others. They are grown to produce cut flowers, but they are also used for garden decoration: the best location is that close to the walls that you want to cheer up with a splash of color, on the top floor of the flower beds to form a colorful and flowery background, in the borders that are planted around the bushes and shrubs to mask their slightly unsheathed stems.
Gladiolus cardinalis (photo www.strangewonderfulthings.com)
Gladiolus byzantinus (photo www.plantsystematics.org)
How it is grown
Gladioli grow well in light, rather sandy but cool soils, in sunny locations protected from winds (hybrids are high and it may be necessary to support them with braces). the bulbs are planted from mid-March to mid-April. Flowering is short-lived and not abundant: each bulb produces only one flower stem. The bulbs must be buried at a depth of 10 cm; if they are intended for the production of cut flowers, they are planted in rows 30-40 cm apart; in the borders they are planted in groups, distancing them by 10-15 cm.
Plants are started to be watered 5-6 weeks after the bulbs are buried; in the warmer periods the watering must be abundant. The gladioli that you intend to use as cutting flowers cut off as soon as the first flower of the inflorescence blooms; in the garden, the inflorescences are cut when they are wilted, but the bulbs are left in the ground until the leaves are completely yellowed (usually in October). At this point, the flower stems can be cut 1 cm above the bulb. Then the bulbs are uprooted, taking care not to damage them, and they are dried for about ten days; finally put in boxes that must be kept away from the cold. During the winter, the bulbs are checked to discard the sick or damaged ones.
Gladioli can be multiplied by means of bulbils and by seed. Bulbils are formed at the base of the bulb and have the size of a pea; they detach themselves from the bulbs when they are extirpated from the ground, that is in autumn,. During the winter they are preserved in the same way as the adult bulbs and in March they are planted outdoors, in 5-8 cm deep solchetti, between two layers of sand. The plants that come out of it must be watered regularly. In autumn, when the leaves are yellowed, the bulbils will be unearthed and stored in the usual moso until the following month of March, in which they replant outdoors. Plants born from bulbils bloom after 2-3 years.
The sowing, which takes place in February-March, is a multiplication method generally used only by nurserymen for the creation of new varieties, since the plants born from seed are usually different in shape and color from the mother plants.
Gladiolus bulbs (website photo)
Species and varieties
- Gladiolus segetum Ker-Gawl .: frequent in all the cultivated places of our peninsula and present throughout the Mediterranean basin. It differs from G. communis for the seeds appendicated below, but not winged. The flowers are purple pink in color.
- Gladiolus communis L .: spread from Spain to Greece, including Italy. It is very similar to G. segetum, but it has the shortest bracts of the flower and the petals almost equal to each other; only the central upper is slightly larger than the lateral petals.
- Gladiolus byzantinus Mill .: species native to the Mediterranean regions, lives in temperate climate zones and does not tolerate cold. Each stem carries 6 to 10 flowers of a beautiful crimson color tending to magenta. The petals are more or less the same and not separated. There is also a rare, white-flowered form.
- Gladiolus cardinalis Curt .: originally from South Africa, it is one of the species from which modern hybrid garden forms derive. It has large crimson flowers 8 cm in diameter, on curved stems. In temperate zones it can be planted and then left permanently in the ground. It does not tolerate frost; it grows well in partial shade.
- Gladiolus grandis Thunb .: species native to South Africa. The flowers in the evening have an intense carnation scent. During the day the color is rust brown while at dusk they change their color to a pale blue and the following morning they turn reddish brown. The color change occurs in about an hour.
Gladiolous - Hybrids: these are the most cultivated gladioli in gardens and those that are cultivated as for cut flowers. None of them tolerate frost but, apart from that, they are quite easy to grow. The varieties are very numerous. The height can vary from 45 cm to 1.5 m; flowering generally lasts a month: to prolong it, it will be better to bury the bulbs in later periods, from March to June, so as to have blooms from June to October.
Hybrid gladioli (photo www.agriproduceindia.com)
Diseases, pests and adversities
The carnation thrips (Thaeniotrips simplex) can cause serious damage to the gladioli. During the winter it overwinters in the bulbs, which become dark and sticky. Later it moves on the stems, on the leaves (silvery spots) and on flowers (spots). If the infestation is massive, the plant cannot even bloom and dies.
Fusariosis of gladiolus is caused by a fungus (Fusarium oxysporium). By storing infected bulbs, these can infect all preserved bulbs.
The scabies of gladiolus is caused by a bacterium, lo Pseudomonas marginata.
Septoriosis is caused by a fungus of the genus Septoria.
Gladioli can also be affected by several viruses. Viruses are transmitted by aphids, cicadelle, nematodes or by contact between healthy and diseased plants, or even with work tools.