Instead of cutting them at the ground, leave about 1 ft.

Jun 22, For the very oldest and most overgrown forsythia, pruning should be brutal, cropping the entire shrub to about 4 inches (10 cm.) from the ground. New shoots will emerge and, with careful trimming, forsythia can be renewed and rejuvenated. Within two years, you’ll have a new shrub.

Keeping your forsythia open allows light and air into the middle of the shrub, which helps it grow healthy.

Jan 03, When to Prune Forsythia. The timing of your pruning depends on what you’re trying to accomplish. The usual advice is to prune after the shrub blooms in early spring. Forsythia bloom on stems that formed flower buds the previous year (called “old wood”) so if you prune before it’s flowered then you won’t have any flowers that year. Jan 08, When to prune Forsythia bushes Like many perennials, spring is the best time for pruning forsythia.

Do this later in the spring after the blooms fade and the leaves are starting to grow.

Blooming will be reduced or nonexistent after a dramatic pruning.

If you wait until summer or fall to trim forsythia bushes, you’ll find that the number of flowers that you get the next spring will be much less than desired. May 22, 1. Prune forsythia plants right after they finish blooming in the spring. Wait for your yellow flowers to fade and for the leaves to grow. At this point, the plant starts to develop next year's buds, and the plant carries the buds through the fall and winter season.

This is the best time to prune your forsythia%. Nov 11, Determining when the bush flowers is part of a successful pruning strategy. Some bushes, such as the forsythia (Forsythia spp.), grown in U.S. Department of. Dec 31, When and How to Rejuvenate a Forsythia. One form of forsythia rejuvenation pruning is to remove one-third of all the branches at their base.

Some people suggest you do this regularly once the shrub is mature. Remove the oldest, branches as they produce fewer flowers over time.