Forsythia ‘Gold Tide’ in summer at NC Arboretum in Asheville, NC

Large Forsythia x intermedia needs annual pruning

Forsythia (Forsythia spp.), also called “yellow bells”, is an extremely popular spring flowering shrub (USDA hardiness zones 5-8). Their bright yellow flowers signal the coming of spring. However, many gardeners do not know how to prune them.

Tall 8-12 foot forms of F. x intermedia are commonly sold at most U.S.  garden centers. Forsythias grow from 2 to 10 feet high and 4 to 12 feet wide depending on species and cultivars. Natural shrub form is arching.  Many forsythias outgrow their space within a few years.

They are frequently planted too close to building and home foundations. What results is clipped boxy hedges or round balls with few flowers. Fall pruning also removes a majority of the pre-formed spring flower buds, which is the main reason you grow forsythia.

Forsythias bloom best in full or partially sunny location. They’re not fussy, growing in any average soi,l and are insensitive to acidic or alkaline pH soils. They have few pest problems although deer browsing in some areas. Spread a slow-release shrub fertilizer in spring if growth is slow or if flowering is sparse.

Prune immediately after flowering has finished in spring. Cut out one-third of the stems to the ground each year to retain its natural arching form plus tip prune to reduce overall size.

Forsythias make excellent specimen shrubs; group several 6-8 feet apart to create a hedge; plant on steep bank for erosion management.

For small sized forsythias, try Gold Tide ® (Courtasol’) that grows 1 – 2 feet tall and  2-4 feet wide. ‘Little Renee’ grows 2 feet tall and 4 feet wide. Goldilocks®  (‘Courtacour’) @ 2-3 feet tall and wide; ‘Show Off’ @ 5 feet tall and 6 feet wide; ‘Fiesta’ @ 5 to 6 feet tall and wide and variegated leaves.