Healthy tubers are the first step to vigorous dahlia bushes. Choose tubers that are free from blemish, chubby and have plenty of growth eyes or nodes. Proper soil preparation and knowing how to fertilize dahlias will also help you achieve the massive plants with prolific blooms that are the goal of any dahlia gardener. Feeding dahlia plants within 30 days of planting will jump start the tubers production of sprouts and stems, while giving the plant enough of the right fuel to enhance flower production and healthy root development. Unlike vegetables and other plants, flowering plants like dahlias need little nitrogen but do need the other two macro-nutrients in higher doses to promote blooms. Keep reading the tips here.