Gladiolus is a perennial flower growing from a bulb-like root structure called a corm. In cold winter climates, this flower is treated like an annual. Gladiolus produce flower spikes that grow 2 to 5 feet tall topped with large funnel-shaped blossoms with ruffled edges. Gladiolus flowers provide color spots of white, pink, red, purple, yellow, orange, salmon, green and bicolored. Growing gladiolus in plant pots allows the gardener to move the flowers around in the garden or landscape. Gladiolus flowers look the best when planted in groups.
Wash a large pot at least 12 inches deep with soap and water. Rinse the plant pot with 1 part bleach to 9 parts water. This eliminates any hiding insect pests and plant disease.
Mix together 2 parts potting soil with 1 part sand to create a good-draining mixture. Gladiolus prefers sandy, rich soil.
Fill the large plant pot halfway with the soil mixture. Mix 1/2 cup of bonemeal into the soil in the pot.
Place your gladiolus bulbs point side up 3 to 4 inches apart in the plant pot. Adjust the soil level so that the bulbs are four times as deep as their diameter. For example, if the bulb is 1 1/4 inches in diameter, it should be planted 5 inches deep.
Fill the plant pot with the rest of the soil mixture. Water the plant pot thoroughly by allowing the water to run out the bottom of the pot. Place the gladiolus plant pot in an area with protection from the wind and full sun exposure.