About all the perennial flowers and garden plants, such as perennial phlox, hemerocallis, funkia, fraxinella, and pie-plant, may be divided by separations, including a bud at the top of each section. In some cases even biennials may be perpetuated by division. As an instance, the double hollyhock flowers the second year from the seed and the year following, when the plants die. But if the fleshy roots are divided after the second year's flowering with a sharp knife, so as to leave a bud at top of each piece, a new lease of life is given. The writer has retained a favorite variety by division a number of years. Such tubers as the dahlia and peony are propagated by division, cutting so as to leave a bud at top of each section. This is true also of such rootstalk species as lily-of-the-valley C5 and canna by making as many divisions as there are buds, or rather separate crowns, as shown in Fig. 32.
Fig. 32. - Divided canna stool. (After Bailey.)
Some of the scaly-bulbed lilies can also be divided and yet remain strong for flowering if separated in sections as indicated by the bulb, as shown in Fig. 33.
As to the time most favorable for division, at the North the spring is the best period for separating hardy perennials, as it is the period of starting growth. But in mild climates the work is usually done in winter or very early spring.
But we have many kinds of bulbous or tuberous plants that make all their growth early in spring and rest in summer, such as the narcissus, hyacinth, tulip, dicentra, and perennial poppy. In such cases the division follows the ripening of the foliage.
With tubers and rootstalks, such as the dahlia and canna, the season for division is in the dormant period in autumn, or prior to time of planting in the spring.
Fig. 33. - Lily bulb showing sections for division.