Approximately 180 species of gladiolus are available to the gardener. Originating from South Africa on rocky slopes, marshy areas and grasslands, they are also found growing in the Mediterranean, Asia and Central Europe. The latin name “Gladiolus” means “small sword”, which is referring to the shape of the leaves and flower spike. They were at one time referred to, as “sword lilies” or “corm lilies”, as the plants are formed from round, flattened bulbs, called “corms”.
The flowers are triangular and funnel shaped, with their six flower petals, or “tepals” as they are called. Each flower usually has one central upper petal, two side petals and three smaller bottom petals. Flowers are available with plain tepals (Dutch origin) and ruffled tepals (American origin). All flowers begin by opening at the base of the flower spike, and as they die more open above, this happening slowly in an upward motion of each spike. Each flower spike produces flowers on only one side and has dark green leaves in a fan shape at the base of the plant. As many as 7 flowers can open at one time on a single spike with 22 buds formed.
Colors are available in a wide range, including: pure white, ivory, yellow, peach, pink, orange, red, lavender and purple. Novelty colors available are lime green and a dark red seemingly black. The only colour not available is a true blue. They can be single colored or bi-coloured and with plain or ruffled petals.
Different cultivars and hybrids available to choose from comprise of many characteristics. Some are dwarf in height and flower size, and bloom late, while others are regular sized and bloom early- or mid-season. The colors, heights and bloom times vary a great deal, thus various types of glads can be seenRead more on backyardgardener.com