Gladiolus plants respond to generous watering during their growing season. Water should penetrate the soil several inches. Waterings at five to seven day or longer intervals may be necessary, depending on soil and weather conditions. Ample amounts of water will result in increased stem length, and possibly better size, color and substance in the blossoms, providing the plants are receiving ample chemical nutrients from the soil.
When cutting spikes from glads, leave at least four leaves on the plant. This is necessary so the plant can store enough food in the corm for the next year’s growth. Each year a new corm is produced over the top of the old one that was planted. The greatest increase in size of the corm is usually after the flowering period. If the plants are robbed of most of their foliage when the spikes are cut, the result will be poor corm development, and therefore poor corms to plant the next year.
Although the frequency of watering glads can be reduced somewhat towards the end of the season, it should not be cut out entirely. In the north areas allow the plants to grow as long as possible in the garden to ensure good corm development. If you live farther south, harvest the corms as soon as the plants begin to show maturity.
If you like to start new glads from cormels (bulblets), you will find this an easy way to increase glads. If you have a planting of cormels, keep them well watered all during the growing season, and never let the soil become too dry. If watering should be cut off for a period, these plants will go dormant ahead of schedule, and you will be harvesting small corms instead of large ones.
Do Glads Change Color?
A question frequently asked is whether or not glads change color. Actual changes in color, known as mutations or sports, are quite rare. Most gardeners who grow glads in mixture believe they do change color. What really happens is that they may have a variety in their mixture that is much more prolific than the others. Some varieties are known to split and produce as many as five (even seven) plants, and consequently five corms from the one corm planted. Many varieties just hold their own, and return just one plant and consequently one corm from the corm planted. Such a variety offers little competition to one that multiplies rapidly. After five years, the variety just holding its own will yield its one corm, if it has lived through the ordeal. On the other hand, you would be harvesting 625 corms of the prolific gladiolus variety, assuming that the original corm and all its off-spring split up into five new corms during each growing season.
If you are still skeptical, keep varieties separate under their variety names. You will soon find that in order to maintain an increase with some varieties, you will have to grow cormels as well as the corms, providing the variety will produce any cormels. With other varieties, you will be giving corms away in a short time.