While you can leave all the shoots to grow, thinning will produce flowers of higher quality. Leave one to four of the strongest shoots. When plants are about a foot tall and display 3 to 4 pairs of leaves, pinch out the terminal shoot to encourage branching. Tall-growing dahlias should be staked to support the long stems and large flowers. Begin staking when the plants are about a foot in height.
Excessive nitrogen can result in foliage production at the expense of flower production.
A second application may be needed on sandy soil or during rainy seasons. When the three buds that form at the end of each branch reach the size of small peas, remove the two side buds. Small-flowering types should not be disbudded. Faded flowers should be removed to encourage continuous blooming. Check plants on a regular basis for diseases, insects, and other pests.