How to Cut a Forsythia

Examine your forsythia bush to determine how much of the bush you need to cut back. Ideally, you want your forsythia shrub to have its branches grow up and out, as if the branches were in a large vase. Horizontal and crossing branches should be removed along with branches that have grown too long. For older bushes that have not been maintained or pruned for several years, cutting may be extensive. Young forsythia shrubs may need less pruning to maintain size and shape.

Use long handled loppers or pruners to remove all dead or broken branches from your forsythia shrub. This can be done at any time during the year, because such pruning will not prevent the bush from flowering. Cut dead branches close to the base of the shrub. For broken or partially dead branches, make your cut an inch below the break or where growth appears. Cuts should be at an angle, with the angle cut pointed toward the ground to limit the possibility of plant disease.

Remove any branches that are touching or laying on the ground. These can root and grow a new forsythia bush too close to a developed bush. Use loppers to cut low-growing branches back to the base of their origin. If a new forsythia bush has already started to grow from a branch on the ground, you can either let it develop a good root system and transplant it to a new location, or dig the new bush out and dispose of it.

Remove branches, or canes, growing in horizontal directions, across other branches or through the center of the bush.

Identify the oldest, generally the thickest, branches of your forsythia bush and cut them off, leaving one third of the branch on the shrub. Older branches are located in the center of the forsythia shrub. Use a hand saw if the branch is too thick for loppers to cut. By removing the oldest branches you will be opening up the interior of the bush for more sunlight to enter, which promotes new growth, more blooms and a fuller shrub.