How to Grow Dahlias

The plants come in all heights from 12 inches to 4+ feet, and the blossoms can range in diameter from 2 inches to 10 inches. They can be grown in full sun in Zones 3-7. In Zones 8-9, they can be grown in a location where they will receive morning light only. In Zone 3, for the longest lasting results, it is recommended that dahlias be grown in containers, and in all zones dahlias make great container plants. The tall varieties will need to be staked. We have found that one application of a timed release fertilizer (6-12-6) after planting is all the nourishment the plant requires, along with ample quantities of water. Dahlias require frequent watering. If left to dry out, they will immediately scream, THIRSTY, with dramatically drooping leaves and stems. During most winters in Zones 6 and higher, the tubers can be left in the ground. In Zones 5 and lower, the tubers must be dug up and stored in a dry basement.

There are many kinds of dahlias and the commercial classifications are not always consistent. Landreth sells 6 different kinds: Dinnerplates, Decorative, Gallery, Pompom and Cactus.

Dinnerplate Dahlias are large plants which produce the biggest blossoms. The plants grow to at least 42 inches high. The blossoms are usually 6-8 inches in diameter. A single blossom from a dinnerplate dahlia floating in an elegant glass bowl will often make a more dramatic statement than an entire bouquet of smaller blossoms.

Decorative Dahlias are usually large plants ranging in height from 36-48 inches with blossoms usually 4-5 inches in diameter, but some decorative dahlias are shorter, 18-32 inches with slightly smaller blossoms. These blossoms make exceptional cut flowers.

Gallery Dahlias are the shortest of the dahlia plants. Most Gallery Dahlia plants are less than 2 feet tall and the blossoms are approximately 2 inches in diameter. These plants make very showy flower garden borders, because once they start blooming, they are usually covered with blossoms. The blossoms can also be used for cut flowers, but often their stems are quite short.

Pompom Dahlias are so named because of the shape of the blossom which forms an almost perfect ball. The plants come in a range of heights. The blossoms make excellent cut flowers.

Cactus Dahlias are so named because the petals of the blossoms are pointed giving the blossom an overall 'spikey' appearance. The blossoms come in some of the most striking color combinations found in nature, and they are some of the showiest of all dahlia blooms. The plants come in a wide range of heights.

For the money invested, dahlias are one of the best values in the ornamental world. From mid-summer until the first hard frost of late fall, these lovely plants will produce a profusion of blossoms which beg to be cut and placed in a vase. The more the plant's blossoms are cut, the more blossoms the plant will produce. For the gardeners who always wants a vase of fresh flowers to grace the home, there is no better flower to choose than the dahlia.