Forsythia mandschurica Seeds | Forsythio Mandshurica
LATIN NAME: Forsythia mandschurica
COMMON NAME: Manchurian Forsythia
Plant Profile
Forsythia mandschurica is a deciduous shrub from Manchuria and the Korean peninsula, growing to about two metres with upright stems that arch at the tips. Before any leaf appears, the bare wood carries four-petalled yellow flowers in April, in clusters at each node, and a mature plant becomes a solid sheet of yellow for two or three weeks.
The leaves follow the flowers and are narrowly ovate with a few coarse teeth, and in autumn they turn a dull purple. It is one of the hardiest of the genus and flowers reliably even after a severe winter. The species is sometimes treated as a form of Forsythia viridissima, the green-stemmed forsythia, and the two are hard to tell apart once the leaves are out.
Science & Biotechnology
The genus was named for William Forsyth, an eighteenth-century superintendent of the Chelsea Phys Garden, and the Chinese species reached Europe in the 1830s through collectors working for the Horticultural Society. Its own place in the genus has been argued over for a century: it was separated from Forsythia viridissima on leaf shape and on the hairs along the young stems, and some treatments keep it as a species while others sink it into that species as a variety.
Molecular work on the genus has found very little divergence among the species, which fits the picture of a group that spread out of China recently and split into a handful of forms that still cross freely. In gardens the result is a swarm of intermediates, and named forms are propagated by cuttings precisely because seed does not come true. The medicinal fruit Lian Qiao is taken mainly from Forsythia suspensa, not from this species.
Uses & Benefits
Forsythia is planted for one reason: it is the first big yellow thing of the year, and it will grow almost anywhere. It is useful as an informal hedge, on a bank, or at the back of a border where its plain summer foliage does not matter much. Branches cut in February and brought indoors open within a week in a warm room, which is why the shrub is forced for early flowers.
Pruning is the thing people get wrong. The flowers come on the previous year’s wood, so cutting the plant into a tight box in spring removes the bloom. Instead, take out a quarter of the oldest stems at the base each year, right after flowering, and let the young shoots arch over. The species has no edible part and no place in Western medicine; its value is the colour it brings when nothing else is in flower.
Growing from Seed
Forsythia seed germinates readily and needs no cold treatment, but it must be sown fresh. Sow in spring on the surface of a light compost, cover with two millimetres of vermiculite, and keep at 18-20 °C in bright light; the seedlings appear in about three weeks. They grow fast and can be potted on within a month of pricking out.
Because the species hybridises so freely, seed from a garden plant will not produce a uniform batch, and if a particular form is wanted, cuttings are the only reliable route: softwood cuttings in June root in three weeks under mist. Plant out in autumn or early spring, in any soil that does not waterlog, and cut the young plant back to 30 centimetres after planting to make it branch from the base rather than run up into a single stem.
Our Take
The earliest yellow of the year, and the toughest forsythia for a cold garden. Prune it after flowering, or not at all.
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