Corms smaller than inch often do not flower the first season. Plant these smaller ones to develop into larger corms capable of blooming in future seasons. To produce glads with large spikes, plant the corms in a location that receives full sunlight. Brighter flower colors and sturdier stalks are produced in full sunlight. Select a location having protection from strong winds.
Glads do well in a variety of soils, but they prefer a sandy loam.
Heavy clay soil may be improved by adding organic matter such as compost, peatmoss or well-rotted manure. The chief soil requirement is good drainage. Poorly drained soil restricts growth and encouraged disease. The better you prepare the soil before planting, the better your glads will respond. Till the soil deeply, digging to a depth of about 12 inches.