Dramatic, spiky gladiolus comes in varieties that range from miniature to giant, and in colors from coolest white to fiery red to vivid pinks and purples. A favorite for cut flower arrangements, gladiolus grows from bulbs that you plant in the spring. Once it starts blooming, it will keep on until nearly frost.
Choose a sunny spot for your gladiolus, about two weeks before the last average frost date in your area. You can find out what that date is by calling your county extension office. Your flowerbed should have loamy soil that drains well, with no other plants in it.
Spade up the soil to a depth of about 6 inches and pull up and discard any weeds you find. Mix in enough compost to make the soil light and somewhat sandy.
Plant the corms between 2 and 6 inches deep; smaller corms should be closer to the surface, larger ones further down. Plant them in rows or groups of ten to 15 and allow five inches of space between the rows or groups. Cover the corms with about 2 inches of soil. When you've finished planting, water the glads well.
When the stems of the plants are about 6 inches tall, mound up more soil around them to support them.
When the stems are between 6 and 10 inches tall, fertilize them with a water-soluble fertilizer, applied four to six inches away from the stems. When the colorful buds are starting to show on the stems, fertilize the flowers again.
Mulch the flowers with 2 to 4 inches of wood shavings, bark or straw to discourage weeds. Pull up and discard any weeds that do emerge in the gladiolus bed. Water the gladiolus plants regularly.