When to prune forsythias

Prune forsythias immediately after they finish flowering, because they bloom on the previous year's growth.

The window: Immediately after flowering, and all pruning should be completed before mid-July to give the plant time to put on new growth and develop flower buds.

Forsythias bloom on the previous year's growth, so the flower show depends on what you leave standing.
Forsythia produces flower buds on current season's growth, which is why pruning right after flowering maximizes next spring's blooms.
For old, neglected shrubs, cut them back to within 4 to 6 inches of the ground in late winter or early spring to rejuvenate them.

The mistake to avoid: Pruning anytime from mid-summer until just prior to bloom will reduce flowering in spring.

Timing varies by region and year; your local extension office is the closest authority.

Grounded in: extension.unh.edu, yardandgarden.extension.iastate.edu. Every timing follows sentences verified verbatim on those pages.

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