When and how do you prune an overgrown forsythia?

Forsythia produces flower buds on current season’s growth, so if you want to maximize the flower show, prune shrubs shortly after they finish flowering. All pruning should be completed before mid-July in order to give plants enough time to put on new growth and develop flower buds.

An overgrown forsythia can be pruned in a couple of ways. One option is to remove a third of the oldest branches shortly after flowering in the first year, followed by half in the second year and the remainder in the third year. Cut branches as close to the ground as possible to encourage new growth to emerge from the base. Use this approach if the forsythia serves as a screen or an important backdrop in the garden. A more severe approach is to cut all of the branches to the ground and let the shrub resprout. This type of total rejuvenation can be done every three to four years in order to keep growth in check and achieve the tidiest possible look to the shrub.