Gladiolus are summer-flowering annuals with showy flower spikes in a variety of colors including white, yellow, pink, red and purple. They require minimal care during the growing season and can also be dug up and saved each year, making them a lasting addition to the spring and summer flower garden. Gladiolus bulbs bloom about 8 to 10 weeks after planting, flooding your garden with flowers throughout the summer.
Plant gladiolus bulbs in spring after all danger of frost has passed. Select a planting site that receives full sunlight and has fertile, well-drained soil with protection from wind. Prepare the soil prior to planting by cultivating with a garden tiller to a depth of about 12 inches. Plant bulbs 3 to 6 inches apart and 4 to 6 inches deep with the pointed side facing up.
Water gladiolus bulbs immediately after planting to settle the soil and encourage growth. Continue to provide water any time the top inch of soil is dry to the touch, usually about once or twice per week, depending on the temperature and drainage of the soil.
Feed gladiolus plants once they reach about 6 to 8 inches in height, usually about one month after planting the bulbs. Use a balanced fertilizer with an NPK ratio of 8-8-8 or 13-13-13 at a rate of 3 to 4 pounds per 100 square feet of soil. Water thoroughly after application.
Apply a 1- to 2-inch layer of mulch over the soil surrounding gladiolus bulbs after growth has emerged. This will control weeds that may compete with the bulbs for nutrients. Use hay, leaves or organic compost to mulch for the best results.
Remove gladiolus bulbs from the ground around the time of the first winter frost. Cut the stems just above the bulbs and cure the bulbs by storing in a shallow container in a warm, well-ventilated area for about three weeks. Remove the withered mother bulb from below the fresh bulb. Store the fresh bulb in a box filled with sawdust or peat moss until spring.