For best results when planting gladiolus, gardeners should choose plants carefully, stagger planting times, and provide plenty of water with adequate drainage. Gladiolus plants grow from structures similar to bulbs, called corms. The quality of a corm is the key to producing strong gladiolus plants with brightly colored blooms. For best results, gardeners should buy corms that are not soft, crumbling, or bruised. Corms that are at least 0.25 inches (6.35 mm) across the thickest part will be more likely to produce blooms.
Using staggered timing when planting gladiolus will lead to enjoyment of flowers throughout the blooming season. To use this staggered approach to planting gladiolus, a gardener can plant groups of corms multiple times several days apart, beginning in late spring. As an alternative to multiple planting times, gardeners could choose to use a variety of cultivars that will bloom at different points in the season.
Whether planted in a garden bed or in a container, gladiolus corms will require frequent watering but must avoid become soggy. The top layer of soil should be loosened when planting gladiolus in order to facilitate sufficient drainage. Gardeners should provide a minimum of 1 inch (2.5 cm) of water on a weekly basis for best results. When planting gladiolus in a container garden, use several corms together. It is essential to use a container with built-in holes for proper drainage and ensure that the container receives full sun.
Outdoors, plant gladiolus in a sunny spot, with the pointy side of the corm facing upward. The holes should be up to 6 inches (15 cm) deep, with this measurement increasing or decreasing relative to the size of the individual corm. Space the corms at least 2 inches (5 cm) apart. Planting gladiolus in a trench with multiple corms is also an acceptable approach, but a gardener who desires to grow gladiolus for the purpose of acquiring cut flowers will find it more convenient to plant the corms in accessible rows.
These perennials can be left to winter in the ground in warmer climates. For harsh winters, remove the corms and store them indoors. Some hardier species of gladiolus are intended to remain underground even in colder winter climates. Gardeners in colder climates could choose to simply replace the old corms annually with newly purchased ones, as if they were annuals.
Gladiolus is available in a wide variety of colors, including shades of red, purple, pink, white, and orange. There are also cultivars of gladiolus that are bi-colored. These perennials are thought to look best in a container with similar types of blooming plants, such as dahlias or lilies.