From our perspective, we gladiolus plants are not true bulbs; we are corms, which are swollen, solid stem bases that store the energy we need to sprout and bloom. Our primary need is abundant sunlight. We require a minimum of six to eight hours of direct sun daily to fuel the photosynthesis that creates strong stems and vibrant flowers. We also demand well-draining soil. Sitting in waterlogged earth will cause our corms to rot, a fate we wish to avoid. A loose, fertile soil bed allows our roots to establish quickly and access the nutrients we need to thrive.
We are tender perennials, meaning we cannot survive freezing temperatures. Therefore, the timing of our planting is crucial for our success. The perfect moment is in the spring, after the last frost date has passed and the soil has warmed to at least 55°F (13°C). Planting us too early in cold, damp soil will delay our growth and could cause us to rot. We patiently wait for the consistent warmth of late spring, which signals it is safe for us to begin our growth cycle and reach for the sun.
To give us the best start, please plant us at the proper depth and spacing. Dig a hole or trench that is approximately 4 to 6 inches deep. In heavier clay soils, a depth of 4 inches is sufficient, while in sandy soil, a 6-inch depth provides better stability and moisture retention. Place us in the hole with our pointed end facing upwards—this is where our shoot will emerge. Space us about 6 to 8 inches apart. This gives each corm enough room to develop a robust root system and access to soil nutrients without intense competition from our neighbors.
Once planted, we require consistent moisture to trigger our growth. Water us thoroughly after planting to settle the soil around us and provide the hydration needed for root development. Continue to water us regularly, providing about an inch of water per week if rainfall is insufficient. As we grow tall and begin to form flower spikes, we may become top-heavy. To prevent us from bending or breaking in the wind, it is helpful to mound soil around our bases or provide discreet staking for support. This ensures our flower spikes remain upright and display our blossoms proudly.
After our magnificent flower spike has finished blooming, you can cut the stem off, but it is vital you leave the foliage intact. Our leaves are our solar panels. Through photosynthesis, they are gathering energy and sending it back down to our corm to be stored for next year's growth cycle. Allow our leaves to remain until they turn yellow and die back naturally. In warmer climates (USDA zones 7-10), we can often overwinter in the ground with a protective layer of mulch. In colder regions, our corms must be lifted before the first hard frost, dried, and stored in a cool, dry place until it is time to plant us again next spring.
