Dahlias are flowering plants that grow from tubers. There are many different varieties of dahlias, and the flowers are available in nearly every color except for black and blue. The blossoms come in several shapes and sizes. There are a few things to keep in mind when you plant dahlias.
Find a place in your yard that receives full, unfiltered sunlight for at least eight hours per day. Dahlias tolerate filtered light in the south, where temperatures are higher. The plants give off more blossoms if they receive full sun.
Dahlias adapt to almost any kind of soil. They flourish and produce more blooms in a soil that is well drained and has a pH level of 6.0 to 6.5. Supplement soil that is too alkaline with an acidic plant fertilizer. Dahlias cannot tolerate soil that retains water. Soil that holds onto water can be amended by mixing in peat moss, manure or compost at a ratio of one to one.
Dahlias grow from tubers, which are like rough, nubby, gnarled bulbs. Plant dahlia tubers 4 to 6 inches deep, with the tuber eyes facing upward. Dahlia tubers planted in moist soil do not need to be watered. Those planted in dry soil must be watered immediately after planting. Thereafter, no additional water is needed until the plants send shoots up through the soil.
Dahlia plants require fertilization every other week. A nitrogen-heavy, water-soluble fertilizer is best. An unfertilized plant will still grow, but the blossom development will be stunted.
Dahlias produce more blooms if existing blooms are cut off. To do this, use gardening shears or very sharp scissors to cut blossom stems from the plant. The cuttings make lovely home decor, and the cut stimulates the plant so it will grow more shoots and blossoms, resulting in a fuller, showier plant.