Cut back perennials

© greenduck

Some perennials can be stimulated to a second bloom through a cut back. These include catmint, lady's mantle, ornamental sage, larkspur and lavender. Cut shoots after first flowering up to a height of 4 inches (10 cm). The new plants will quickly drive out and usually bloom again after a few weeks. Water regularly during a drought. A fast acting mineral fertilizer will give the plants necessary power for a second bloom.
If your Larkspur's vitality had let something to be desired, you should not just cut it back after flowering, but now dig it up divide it and plant the strongest pieces again.