For most Canadians, seeing the brilliant golden blossoms of forsythia bushes as they burst riotously into bloom each year is one of the first sure signs that spring has finally arrived. But although they’re such a familiar sight in our northern gardens, they’re actually relative newcomers to Canada.
Precocious forsythias represent a botanical team effort: Asian plants hybridized in Europe and North America and named after a pushy, rather unscrupulous Scottish horticulturist, William Forsyth (1737–1804), who died long before he could have a shufti at his namesake.
In warmer regions (Zones 5 and up), the most commonly seen types are crosses between two species of Chinese forsythias—weeping (Forsythia suspensa) and greenstem forsythia (F. viridissima)—that were developed in Berlin about 100 years ago; these plants are now known as F. x intermedia. And more recently, the Korean early forsythia (F. ovata) has been hybridized to produce plants with improved flower bud hardiness. These are the best choices for gardeners in colder areas.
- Site plants in average garden soil in full sun for optimal flowering.
- Prune immediately after flowering; the following year’s buds are set in late summer.
- Maintain plant vigour, good air circulation and light penetration by pruning out the oldest and thickest canes every two to three years.
- Rescue overgrown specimens with radical pruning: cut all canes 15 to 20 centimetres from ground level; after six to eight weeks, thin the resulting new shoots by half.