Which Side of the Gladiolus Corm Goes Down?

Preparation

• Before you plant the gladiolus corms, prepare the planting bed by loosening the soil to a depth of about 12 to 15 inches, using a rototiller or garden fork. Spread on top of the bed a 2- to 4-inch-thick layer of compost, and mix the compost into the soil. Depending on the size of the corm, plant it 3 to 6 inches deep into the soil -- with larger corms planted deeper than smaller ones. Space the corms as close as 2 or 3 inches apart or as wide as 6 inches apart. If you're planting rows of gladioli, space the rows 20 to 36 inches apart.

Planting

• Plant gladiolus corms in spring, after all danger of frost has passed, with the pointed end of the corm facing up and the rounded, flatter side facing down. Plant the corms in a staggered single or double row for the best appearance. If you're planting taller gladioli varieties, insert stakes into the ground beside the planted corms for support as the glads grow. After you set the corms into their planting holes, cover them with soil and press the soil down firmly.

Tips

• To control weeds and regulate soil moisture around your gladioli, spread a 2- to 4-inch layer of mulch on the ground around the flowers. Water the glads deeply and thoroughly weekly during summer when rainfall is less than 1 inch. Soak the ground well when watering glads. Fertilize the gladioli when the plants are about 6 to 8 inches tall, applying 3 to 4 lbs. of a 5-10-10 NPK fertilizer formula per 100 square feet of bed area. Pick off the individual flowers as they wilt and fade, and allow the foliage to die back and act as mulch for the corms.

Warnings

• If you plant the corms upside-down, with the pointed end facing downward, the stem likely won't grow. If you live in a region where winter temperatures dip below 0 degrees F, dig up and store the gladiolus corms in fall, before the first frost. Replant the corms the following spring. In warmer climates, simply spread extra mulch, such as straw or hay, on top of the soil to provide extra winter insulation for the corms.