Plant with the roots at approximately the same depth as for tuberous types. Propagation by dividing the clumps of tuberous roots is easiest. Divide the clumps with a sharp knife in March or April. Buds will be easier to detect if you place the roots in a warm, moist place for a few days before dividing them. Culture Dahlias should be planted in an airy, sunny place protected from high winds.
Dahlias do well in fertile, well-drained garden soil.
Improve heavy clay soils by incorporating well-rotted manure, peat, or compost. Work a two to four inch layer of organic material into the soil in the fall or three to four weeks before planting in the spring. Top dress with this material at the same rate in late July. Avoid getting the fertilizer on the plants. Rake the fertilizer into the soil and then water.