What Ground Temperature Do Gladiolus Actively Grow At?

Temperature and Light

• The ideal soil temperature for gladiolus growth is at least 55 degrees Fahrenheit, according to horticulturists with Clemson University. Take the soil’s temperature at a depth of 6 inches. Cooler soil temperatures, especially when moisture is present, may cause the gladiolus corm to rot. Freezing temperatures may kill the gladiolus corm, so most gardeners in regions with severe winters dig up the plant and store the corm over the winter. Flowering is at its best when air temperatures range between 59 and 72 degrees. Gladiolus grows in sun or shade, but flowers are larger, with stronger stalks, when it is grown in full sun.

Moisture and Fertilizer

• Although easy to care for, gladiolus is not one of those plants you can stick in the ground and neglect and expect it to thrive. During dry periods, provide the glads with at least 1 inch of water a week. Avoid frequent waterings – provide the inch of water on one day, soaking the soil completely. Apply 3 pounds of 5-10-10 fertilizer per 100 square feet of gladiolus bed when they reach 6 inches in height and again when the gladiolus produces the flower stalk.

Pests

• The most troublesome pest on the gladiolus is thrips. These tiny insects hide among the flowers, feeding on both buds and mature blooms. If you see white streaks on the glad’s foliage, or deformed flowers, suspect thrips. Remove heavily infested gladioli from the garden. Prevent a thrips infestation by using Sevin dust as soon as the gladiolus reaches 6 inches tall. Reapply every week. When you dig the corms in the winter, place them in a bag and sprinkle Sevin over them. Close the bag and gently shake it to coat the corm with the pesticide.

Considerations

• For maximum gladiolus production, plant corms throughout spring, a week apart. This will provide the garden with color throughout the summer. If you grow glads for cut flower arrangements, it’s easiest to plant them in rows, as you do with vegetables. Wait until the first flower on the stalk has color and then cut the stalk. The remaining flowers open while in the vase. Allow the foliage to die back and dig up the corm before the first freeze in your area. Store at 45 degrees Fahrenheit. Gardeners in warm-winter regions can leave the corms in the soil and cover them with a 2-inch layer of mulch.