Byzantine gladiolus (Gladiolus byzantinus) is a native of southern Spain, Sicily, and North Africa. It has green spear like foliage and scarlet flowers. In fact, it gets its name from the similarity between the leaves and a gladiator’s sword. It is considered an heirloom. It was introduced in 1576 in the Byzantine empire. It is difficult to find true Byzantine gladiolus at nurseries now but they are well worth the effort in locating them.
Byzantine gladiolus is planted by planting the corms that are the part of the plant between the roots and the foliage. These corms are different than corms from hybrid types of bulbs. They are smaller. They can be planted as deep as eighteen inches and still grow. Corms are planted in the fall or in early January and February. In the spring, first the foliage grows, then the buds of the flowers. These buds are very attractive in of themselves, but in early summer the blooms open and put other gladiolus to shame.
To propagate these wonderful plants, plant the corms in the fall, or, if you have harsh winters, in January and February, about three inches deep and four to five inches apart. Water well. Byzantine gladiolus needs the sun to be at their best. They will need supplemental water all during their first year. Water them once a week with an inch of water at a time. This promotes deep root growth. Water from the bottom to prevent fungal infections from getting a hold on your wet leaves. It is best to water in the early morning so if some water gets on the plant, it will soon evaporate in the sun.
Byzantine gladiolus requires fertile, well drained soil. If your soil is not so fertile, such as clay soil, you can till the ground to a depth of six inches, then put three inches of compost on top of the tilled area. Till the compost in completely. You now have fertile, well drained soil ready to plant your glads in.
These plants make excellent cut flowers, so grow some extra for that purpose. When they are through blooming, deadhead the flowers and allow the foliage to remain. When it dries up, but the foliage down to the ground to keep the garden looking tidy. In most climates, the Byzantine gladiolus can survive the winter and will bloom in April or May.
Byzantine gladiolus need to be fertilized with a good balanced fertilizer, such as 10-10-10, when they begin to form flower buds. This gives them the nutrients and energy they need to grow such spectacular flowers.
In very cold climates, colder than zone 6, you will have to dig up the corms and store them in a cool, dry place for the winter. In the early spring, you will have to plant them again. They will bloom again that year so all you lose is a little time. However, the beauty of the flowers makes that worth the effort.