You can plant dahlia tubers straight into the ground, although it is important that the tubers are planted in an area that has fertile and well drained soil.
There are many different ways to plant dahlia tubers. If planting into the ground you can grow them in rows, or just plant them in a sunny spot in your garden.
Space tubers 1.5 to 2.5 feet apart, depending on the size of the dahlia variety. Do not water your dahlias until they are up through the soil and growing well.