Gladioli, popular around the globe, come in a wealth of colours and sizes, from standard to dwarf. Standard cultivars, with tall, stately stalks, reach up to 6 feet in height, while most dwarf gladiolus cultivars grow from 1 to 2 feet tall. Growing from bulblike corms, gladioli thrive in full sunlight and produce stunning, trumpet-shaped blooms in a rainbow of colours. Dwarf gladioli bring all the magnificence of their taller counterparts without the hassle of staking, making these specimens perfect for cutting gardens, borders and containers.
Incorporate 1 to 2 inches each of coarse sand and organic compost into the chosen planting site at a depth of 10 to 12 inches to create a sandy loam. Although gladioli grow in a variety of soil conditions, they need good drainage for optimum growth. Sand and organic materials allow excess water to drain away while retaining the right amount of moisture and nutrients.
Choose a layout for the dwarf glads. If you wish to use your glads for cut flower arrangements, plant them in staggered, straight rows for easy cutting access. For flowerbeds and borders, plant corms in groups or wherever preferred to complete your desired bed design.
Dig a furrow according to the size of the gladioli corms. The University of Minnesota Extension Service recommends planting corms at a depth of four times the diameter. For example, a 1-inch corm should be planted 4 inches deep. Allow enough room in the furrow to provide at least 6 inches between corms.
Space gladiolus rows at least 18 inches apart to allow space for working during the growing season. For mass plantings or cutting gardens, allow at least 2 feet between rows for easier access, especially when harvesting.
Plant corms in the furrows, placing the pointed side upward, and cover over with soil.
Pat soil down over corms and water to set in place.
Apply a 1- to 2-inch layer of mulch over the rows to help retain moisture and keep weeds at bay.
Plant dwarf glads from May to mid-June. Planting corms every two weeks during this time frame allows for consistent blooms through the end of the growing season. Label different varieties as you plant them to keep corms organised when you dig them up in the fall.