Gladiolus, a perennial plant that grows from a corm, is generally cultivated for its flowers. When in full bloom the plant can reach a height of 2 to 6 feet. Flowers bloom in mid-summer, on long stalks, in a multitude of colors from pale pastels to vibrant primary colors. Gladiolus is easy to grow in just about any climate and will bloom from spring to fall.
Grow your gladiolus in well-draining soil in a sunny area with no wind. Spring and fall are the best times to plant gladiolus.
Water every week during the summer and when the weather is dry. Horticulturists from the University of Minnesota recommend giving the gladiolus an inch of water a week.
Apply a water-soluble, 20-20-20 fertilizer, at least 5 inches from the base of the plant, when the gladiolus reaches 10 inches tall. Apply again when the flower spike begins to form.
Cutting gladiolus flowers should be done when 2 or 3 of the florets on a stalk open. Cut diagonally and immerse the stems in warm water. Allow them to soak in the water, in a cool, dark area for a few hours.
Keep pests away by clearing away all weeds and any dead or dying organic matter from the flower bed. Gladiolus is prone to infestations of tiny insects called thrips. You can protect the young gladiolus, those over 6 inches tall, by dusting the leaves with Sevin dust.
Dig up the gladiolus corms 4 to 6 weeks after the plants have stopped blooming. Wash off the soil and place the corms in the sun for 2 to 3 weeks. There will be an old corm on the bottom, remove it and throw it away. Dust the corms with an all-purpose fungicide and store them in a mesh or net bag, at 35 to 45 degrees F, until you are ready to plant them next season.