Gladiolus is a classic plant known for its tall flower spikes. A great cutting flower, gladioli look beautiful in midsummer bouquets. Here’s how to grow gladioli in your garden. Available in a multitude of colors, gladioli grow between 2 to 5 feet in height. Gladiolus flowers are liked by the people all over the world. It is a perennial flowering plant which has sword shape leaves, funnel shaped perianth and spoon shaped branches. The flowers bloom mainly in the month of October-March. It produces wide range of flower color ranging from pink to reddish, light purple to white, or white to cream or orange to red.