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"Growing the Many Different Types of Dahlias" In late summer, as the summer-blooming perennials begin to wind down, the annuals are beginning to look just a little tired, and the autumn-blooming perennials have yet to begin their show, there is one plant that really comes into its own - dahlia. Dahlia is a tender bulb that begins to bloom in mid summer, but really puts on its best show in late summer, right up until frost. It offers a showy burst of colorful flowers late in the season at a time when other flowers have begun to fade. Dahlias have some of the largest flowers in the late summer garden. It's hard to outsize a dahlia flower, especially those types appropriately nicknamed "dinnerplate" dahlias. Some do come close in size to a dinner plate. One variety in particular, 'Kelvin Floodlight,' has huge, bright yellow, many-petaled blooms that are easily eight inches across. Dahlias come in a wide array of flower shapes, sizes, and colors, as well as overall plant size. Dahlia flowers are available in every color except blue. Many varieties have bicolored flowers as well. Dahlias are classified by the look and shape of their flower. Classifications often refer to a flower type they resemble. Flower shape classifications include single, cactus, semi-cactus, incurved cactus, pompon, ball, collarette, formal decorative, informal decorative, orchid, peony, waterlily, anemone, miniature, and lilliput. The single-flowered types have a single ring of flower petals surrounding the center. Flowers can reach up to four inches across. Plant size is usually a foot and a half to two feet tall. Cactus-flowered dahlias have fully double flowers made up of many slender, pointed florets, similar to cactus flowers. Often the flower petals are rolled inward, resembling quills. Cactus dahlias have some of the largest flowers. It is not uncommon to have flowers 10 inches wide or more. Cactus types are also tall plants, easily reaching five feet tall. Semi-cactus dahlias have flower petals that are flat near the center then form a tube at the outer edges. Like cactus-flowered types, semi-cactus also has large flowers on tall plants. Incurved cactus dahlia flowers closely resemble cactus types, but the flower petals of incurved cactus types curve inward rather than outward. As with cactus types, incurved cactus varieties have large flowers on tall plants. Pompon dahlias have fully double flowers arranged in a tight clump, and usually have rounded-edge florets. Pompon dahlia flowers are generally small, averaging two inches or less across. Plant height ranges from two to four feet. Ball dahlias closely resemble pompon types but with an even more rounded appearance. The short flower petals are very close together and appear to spiral outward from the center. Ball-type flowers are four to six inches in diameter. Miniature ball dahlias have the same type of flowers as the ball-types, only smaller. All are less than four inches wide. Both types grow up to four feet tall. Collarette dahlias have single flowers with two rows of petals arranged around the center. The inner row of petals are shorter than the outer row and are usually a different, contrasting color than the outer petals. Flowers are up to four inches across. Plant height ranges from two and a half feet tall to four feet tall. Formal decorative dahlias have flowers with numerous flower petals. The flower petals are evenly spaced and each petal in each row is identical in length. Flower size varies with formal decorative types, from miniatures under two inches wide to giants over 10 inches across. Formal decorative dahlias are large plants, as well. They can reach five feet tall or more. Informal decorative types have flowers with long petals that are sometimes twisted. Unlike the formal decorative, the flower petals of informal decorative dahlias are not evenly spaced around the flower. Flowers are four inches wide or more on plants up to four feet tall. Orchid dahlias have striking, star-shaped flowers. The open-centered flowers have long petals with ends that curve backward. Flowers are generally four inches wide or more. Peony dahlias bear open-centered flowers. Surrounding the center are two to three rows of flower petals. The petals are often curled or twisted. Flowers range from less than five inches across to over eight inches wide. Plants are usually three feet tall or so. Waterlily dahlias have flowers that closely resemble a waterlily. The fully double flowers have a flattened shape on the outer edges and the inner petals appear to close around the center. The flower petals are flat with a slight curve on their outer edges. Flowers are generally up to six inches across on four-foot-tall plants. Anemone dahlias have one of the more unusual flower shapes. Arranged around the outer edges of the flower is a single row of wide, flat petals. Sitting atop the outer petals is a clump of small, tubular petals, often in a contrasting color. Plant size ranges from two to three feet tall with flowers up to four inches wide. Miniature dahlias are a smaller version of all the different classifications of flower types except ball and pompon. Plant size is small, under four feet tall, and flowers range in size from two to four in