Forsythia viridissima (21/04/2013, Kew Gardens, London)
Position: Full sun to light shade
Flowering period: Spring
Soil: Moist, well drained
Eventual Height: 3m
Eventual Spread: 3m
Hardiness: 6a, 6b, 7a, 7b, 8a, 8b
Family: Oleaceae
Forsythia viridissima is a deciduous spring flowering shrub with an upright habit. Its mid green leaves are lanceolate with serrate margins, up to 15cm long and 4cm wide. The yellow, four lobed flowers are located singularly in the leaf axils, are up to 25mm long and appear before the leaves. Its fruit is a dry, ovoid capsule, contain winged seeds and appear in late summer. Its branches may root where they touch the ground.
Forsythia viridissima, commonly known as the Green Stemmed Forsythia, is native to east China. In its native habitat it grows woodland margins.
The etymological root of the binomial name Forsythia is named after William Forsyth (1737-1804), the superintendent of the Royal Gardens in Kensington and St. James Palace and founder member of the Royal Horticultural Society. Viridissima is derived from the Latin viridis meaning ‘green’.
Forsythia viridissima Flower (21/04/2013, Kew Gardens, London)
The landscape architect may find Forsythia viridissima useful as a spring flowering shrub. This shrub is not attractive to deer.
Ecologically, Forsythia viridissima flowers are attractive to pollinating insects.
Forsythia viridissima prefers moist, fertile, well-drained soils. It tolerates most pH of soil.
Forsythia viridissima requires little maintenance. If required, pruning should be carried out after flowering.
landscape architect's pages 
Two species of forsythia are at the heart of the selected forms, for both species are variable, and garden hybrids: Forsythia suspensa and F. viridissima. “These two species are, as it were, the founder-members of the forsythia family” writes Alice Coats; they were the earliest species brought into Western gardens from the Far East and they have each played a role in the modern garden shrubs.
Who needs flowers? Plant this non-flowering dwarf forsythia for its leaves which emerge chartreuse with a lime green central vein and then age to a creamy white. The fall foliage will mature to bright burgundy on this compact and tidy selection.