Gladiolus and Dahlia - Popular Summer Flowering Bulbs

Gladiolus and dahlia plants may be planted in April. They are ideal plants for sunny, well-drained locations. In addition to their landscape display, they provide excellent cut flowers. Other summer bulbs may be used in locations these two types may not fit. For moist shade, tuberous begonias and caladiums might be used. For heavy fragrance, the tuberose and Peruvian daffodil are possibilities. For a tropical look in a wet spot, elephant ear provides huge leaves but no flowers.

Some gardeners do not like the extra effort required in digging and storing these bulbs in the fall, but the display and uniqueness of many are often enough to make the extra effort worthwhile. Gladiolus should not be grown in areas where soils are heavy. They need full sun, although afternoon shade often helps to extend bloom life if they are not to be used for cut flowers.

Although drainage must be good, the plants need ample water when flowers and plants are developing. After plants are well established, a side dressing of a fertilizer such a 5-10-15 about six weeks after planting maintains vigor. It should be placed in a band four to six inches from the base of the stems. If gladiolus bulbs are to be used for landscape display, plant them as close as three inches, but to get the best flowers for cutting or exhibition, they should be spaced at least six inches apart. When planted in rows, they should have 20 to 36 inches between rows, depending on space available and equipment used.

A serious insect pest of the gladiolus is the thrip. Thrips cause malformation of the flowers and streaking of the leaves. Frequent application of an insecticide such as diazinon, is sometimes necessary to control them.

Dahlias have more to offer for landscape use than any other summer-flowering bulb. Plants may be bushy and low, or up to eight feet tall. Flowers have many sizes, shapes, forms and colors. The bushy, low-growing types are most often grown from seeds, and may be purchased with summer annuals as started plants. The tall-growing varieties, which often have large spectacular flowers, are purchased, not as plants, but as root divisions.

Although modern dahlia varieties often flower in the hottest weather, their best flowering and colors develop in the fall as weather cools. Dahlia roots from last season should be divided before planting. Each division must contain at least one "eye," which is the bud located near the point where the root grows from the stem. If a root breaks off without his eye, it is not able to form a shoot and new plant.

Dahlias grow best where they receive full sunlight and have a very fertile soil. Although they need good drainage, they are vigorous growers that must have plenty of water at all times. Fertilizer, composted manure or other soil-improving material should be added to the average soil when preparing for dahlias. Since they need a high fertility, side dressing with a fertilizer in July will give them a boost for the fall.

http://en.wikipedia.org/wiki/Gladiolus
http://en.wikipedia.org/wiki/Dahlia