DESCRIPTION: This large group consists of about 250 to 300 species of gorgeous, tender perennial corms, which are mainly natives of South Africa, although some are found wild in west and central Europe, the Mediterranean to southwest and central Asia, and northwest and east Africa. The name Gladiolus is Latin for small sword and refers to the shape of the leaves, thus these plants have been commonly called Sword Lilies and Corn Lilies. These plants are suitable for growing in borders, flowerbeds and containers and are excellent cut flowers. Thousands of varieties have been derived from the common Gladiolus, G. hortulanus, and come in an extensive array of colors; they produce flowers in every shade except blue and may be bi- or tri-colored. These plants produce fan-like clumps of sword-shaped leaves and range in height from 2 to 6 feet. In the spring, summer, or fall they bear long spikes of trumpet-shaped blossoms. The flowers open first at the base of the spike with the older ones dying as the new ones unfurl. The flowers may be frilly, ruffled, or plain and range in size from 1 inch in diameter up to 8 inches in diameter. Healthy plants produce two dozen or more flowers on a single stem.
POTTING: Gladiolas are hardy from zones 7 to 10. They will grow in many different types of soil, although a well-drained loam or sandy loam is best. Soil that is too heavy and clayey can be corrected by adding organic materials such as compost or peat moss. Too light soil can have compost and thoroughly decayed manure added. Soil with a pH between 6.0 and 6.5 with a medium fertility will give the best growth. Choose a sunny location sheltered from wind and add 2 pounds of a 5-10-5 fertilizer to each 100-sq. ft. of space or mix some directly into the corm's planting hole. Sprinkle it on top and dig it in to a depth of 6 to 8 inches. Plant the corms in the spring, 4 to 6 inches deep and 4 to 6 inches apart. In hot-summer regions, plant the corms in the winter so they will bloom before the summer's heat hits. It is better to grow them in large clumps rather than straight lines because of their height and slenderness. They are also seen to their best advantage when one variety is planted per group with taller varieties placed at the rear. You will probably want to stake their stems, especially those of tall varieties to prevent them from falling over. It also helps to plant the corms deep. Gladiolas take from 60 to 100 days to bloom once planted. This may be hastened with an application of a low-nitrogen fertilizer a month after planting and again when the flower spikes begin to grow. During the summer, cultivate the soil around your plants to keep weeds down, but take care not to damage their shallow roots. Placing mulches, such as straw, sawdust and wood shavings, around your Glads will help conserve moisture and prevent the growth of weeds. Water liberally during the growing season and during bloom, especially during dry spells. They should receive an inch of water per week. It is better to give a good soaking rather than a light sprinkle daily. The old flowers should be kept picked. When using the blossoms for indoor decoration, cut the spikes when the first floret is showing color. Insert a sharp knife above the second to fourth leaf and make a slanting cut upwards. Place the spike in water right away to prevent wilting. Make sure to leave at least two, better yet four, leaves on the plant after cutting spikes to help the corms mature properly. In areas where they are hardy, Glads can stay in the ground; elsewhere, in the fall before a hard freeze, dig the corms up and store them uncovered in a well-ventilated, cool spot (35º to 45º F). After digging up the corms, remove the soil and cut the tops to within 1/2 inch or so above the corm. After a few days, when they are drier, remove the old corm from the base. Sort the corms and small corms according to size. The small corms (or cormels) can be saved and planted the following year, but it will take two or three years to produce a blooming-size corm from them. The most troublesome pest to Gladiolas is the thrip. Thrips work on the buds before they emerge from the sheaths and causes malformed and spotted flowers. They may overwinter on the corms. There are thrip insecticides available. Other pests that may cause damage to the leaves or flowers include aphids, cucumber beetles and grasshoppers. There are many diseases that Gladiolas are susceptible to. When planting in the spring, check the corms for any signs of disease by pulling back the husks and examining the inner surface.
PROPAGATION: Gladiolus corms can readily be purchased at your local garden center or nursery, though they can easily be grown from seed. Sow the seeds in early spring, in a well-drained flat 8 to 10 inches deep, that is filled with two thirds loam and one third leaf mold or peat moss, with a good amount of sand added. Plant the seeds an inch apart and cover with about 1/4-inch of the soil. If the soil is kept fairly moist, the seeds should sprout in a few weeks. Set the container of seedlings outside in a fairly sunny location during the summer months and don't disturb until the leaves have died down in the fall. At this time, take out the small corms, store for the winter, and plant in a border in March about 3 inches apart.
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