Here is a guide to thriving in the Southern US, written from our perspective as Gladiolus plants. To truly help us flourish, it is essential to understand our needs from our point of view.
We are not true bulbs but corms, which are swollen stem bases. We crave a well-drained bed above all else. The heavy, clay-rich soils common in the South can lead to our rot, especially during your humid summers. Please plant us in a raised bed or amend the native soil generously with compost, peat moss, or coarse sand to ensure excellent drainage. While we adore the sun, the intense Southern afternoon heat can be stressful. A location with full morning sun and some light afternoon shade is ideal for keeping our foliage vibrant without scorching us.
Your long growing season is a blessing we can fully exploit. You can plant our corms successively from early spring, after the last frost, all the way through mid-summer for a continuous display. Place us about 4 to 6 inches deep with our pointed end facing upwards. This depth is crucial—it provides stability for our tall flower spikes and protects us from the surface heat. Space us 6 to 8 inches apart so we have room to grow and air can circulate between us, reducing the risk of fungal diseases.
To send up our magnificent flower spikes, we require consistent moisture and nutrition. Water us deeply once a week, providing about an inch of water, especially during dry spells. The goal is to keep the soil moist but never waterlogged. A layer of mulch around our base is immensely helpful; it conserves moisture, suppresses weeds, and, most importantly, keeps our roots cool. Feed us with a balanced, low-nitrogen fertilizer or a bulb-specific formula when our shoots are about 10 inches tall and again just as our flower spikes begin to show color.
Once our beautiful flowers have faded, the most critical part of our life cycle begins. Please do not cut down our foliage! We need our green leaves to continue photosynthesis, gathering energy from the sun to store in a new corm that will form on top of the old one. Allow our leaves to yellow and die back naturally. In the warmer zones of the South (8-10), you can often leave us in the ground over winter with a thick protective mulch. In marginally colder areas, or if you want to ensure our survival, lift our corms after the foliage has died, dry us in a warm, airy place for a few weeks, and then store us in a mesh bag in a cool, dry, and dark place until spring planting time returns.
