Dahlias (Dahlia pinnata) come in a wide array of colors, flower shapes and sizes. To bring spring color to your garden early, start your dahlias indoors about six weeks before the expected final frost in your area. When the weather warms up, your dahlias will be ready for transplant outdoors. Dahlias can serve as hedging or border plants for your flower garden, or as wall cover if planting larger varieties.
Pinch back any dahlia plants that have grown taller than 12 inches. Keep your dahlias indoors until the soil temperature reaches 60 degrees Fahrenheit.
Dig a hole about 12 inches deep and 12 inches wide in a sunny area of your garden. Combine the removed soil with a few cups of compost, a handful of bone meal and a bit of lime.
Shovel the soil mixture into the hole until it is about 6 inches deep. Remove the dahlia from its container and place the tuber in the hole. Fill in around the base of the dahlia with the remaining soil.
Moisten the soil around your transplanted dahlias for a week to allow the roots to establish. Continue deeply watering your dahlias once or twice a week and apply a liquid fertilizer diluted to 1/4 strength once a month.