Dahlias are enchanting summer bloomers with a variety of styles to suit every taste. They are available in double and single varieties and in sizes ranging from tiny pompons to blooms more than 10 inches in diameter. Hues span the spectrum from white to bronze, dark pink to bright red, yellow to orange, lavender to dark purple and other colors in between. Although dahlias look exotic, planting dahlias is surprisingly simple. Plant dahlias in late April or early May when the ground has warmed and all danger of frost has passed.
Select a planting spot where the dahlias will be exposed to at least six hours of sunlight per day. Prepare the soil a week before planting. Use a garden fork or a spade to cultivate the soil to a depth of 8 to 10 inches, then work in a balanced granular fertilizer. Read the fertilizer package label carefully for specific rates of application.
Drive a 5-foot tall wooden stake into the ground before you plant the dahlia tubers, because the grown dahlia plants will require support. Installing the stake before planting will prevent damage to the tuber later. Tie the dahlia to the stake when the plant is 10 to 12 inches tall, using soft garden twine or a strip of pantyhose. Plant a dahlia tuber on each side of the stake so that the stake supports both plants.
Dig a hole 6 to 8 inches deep approximately 6 inches from the stake. Place a dahlia tuber horizontally in the hole. Cover the tuber with soil.
Water immediately if the ground is dry. Don't water again until you see a shoot emerge from the soil. After a shoot has emerged, give the dahlia about an inch of water every week.
Spread 1 to 2 inches of organic mulch around the dahlia plant. Mulch such as pine needles or shredded bark will keep the roots cool and moist.
Fertilize the dahlia in July using a balanced granular fertilizer. Apply the fertilizer according to the directions on the package.