How to Transplant Pyrethrum

Select a planting bed in a sunny location that is free from heavy shade. Prepare a soil bed of dry, gravelly soil. A sloped location is ideal. Avoid humus-rich or loamy soil, as well as shady areas, if you are trying to increase pyrethrin concentrations in the flowers.

Dig a hole the size of the plant's root ball and place the plant in the hole so the top of the root ball is level with the soil. Space the plants 12 to 20 inches apart in rows at the same distance for multiple transplants. Not all chrysanthemums will survive the trauma of transplanting; 15 to 30 percent may die off, according to McGill University's Ecological Agriculture Projects.

Dig around the flowers' root systems if removing them from a bed. Remove carefully to avoid damage to the root system. It is often easiest to wait until plants are nearly root bound, but not constricted, before transplanting from pots. Gently remove the plants from their pots and squeeze the root ball between your fingers to encourage the roots to expand, if pots are root-bound. Seedlings should be about three months old before transplanting.

Provide regular water to keep soil evenly moist.

Pinch plants by removing the top growth of the stem once they reach 6 to 8 inches tall. This will encourage extra branching and more blossoms. After the first bloom, cut the stems back to promote a second bloom.

Weed regularly to prevent competition from other plants. Chrysanthemums are sensitive to invasion from weeds.

Divide the plants in spring if they become overcrowded. Separate clumps of plants using a sharp knife or spade and replant in a new location with sufficient spacing.