Chinese wisteria

Synonyms: Chinese wisteria, Wistaria chinensis, Glycine sinensis Sims, Kraunhia floribunda var. sinensis (Sims) Makino, Millettia sinensis (Sims) Benth., Rehsonia sinensis (Sims) Stritch, Wisteria praecox Hand.-Mazz., Wisteria chinensis

Wisteria chinensis – a species of flowering dicotyledonous plants in the genus Wisteria (Wisteria) of the family Fabaceae. In nature it grows in mountainous forests at elevations of 500–1800 m above sea level in central and eastern China (provinces Anhui, Guangxi, Fujian, Hubei, Hebei, Henan, Jiangsu, Jiangxi, Shaanxi, Shanxi and Shandong), and is also found in Japan. It was first brought to Europe and introduced into cultivation in 1816. In Ukraine it first appeared in Odesa in private cultivation in the early 19th century. The first specimen in the Nikitsky Botanical Garden appeared in 1826.

It was described by the English botanist John Sims in 1819 and placed in the genus Glycine, and in 1825 was transferred to the genus Wisteria and described by the well-known Swiss-French botanist Augustin Pyramus de Candolle.

Members of the species are woody climbers that reach 20–25 m in height. Stems twine counterclockwise, reaching a diameter at the base of 25—30 (40) cm. Young shoots are covered with whitish pubescence, later becoming glabrous. Bark dark gray, fissured; young shoots light green, covered with silky short hairs directed backward.

Leaves alternate, petiolate, imparipinnately compound, up to 30 cm long, composed of 7–13 oblong-ovate or ovate-lanceolate leaflets, 5—8 cm long and 2—4 cm wide, base rounded or slightly cuneate, apex acute, less often attenuate, curved, with ciliate margin, appressed-pubescent on both sides, later almost glabrous above, below lightly pubescent and paler.

Blooms in spring, from April to May, with possible repeat flowering in August–September. Flowers are in racemose inflorescences, consisting of numerous bluish-violet or white flowers 2–5 cm long, with a weak fragrance. They grow at the tips of shoots or in the leaf axils of two-year-old shoots. The inflorescence axis is pubescent. Perianth zygomorphic. Petals 5. Pedicel 2–3 cm long.

Fruits are densely pubescent pods 10–15 cm long and 1.5–2 cm wide, gray-yellow, dehiscent. Seeds 1–3 per pod, reniform-round, yellowish-brown, shiny, 1.5 cm in diameter. Fruits ripen in October.

Chromosome number 2n = 16.

Hybrids: Wisteria × formosa — a hybrid of Wisteria chinensis and Wisteria floribunda (Wisteria floribunda).

Forms: white (f. alba), double (f. plena), 'Sierra Madre', 'Prolific'

Hardiness zone: 6 (−22°C). Young plants require winter protection. Performs well in Crimea, Transcarpathia, the Pre-Carpathian region (Lviv, Chernivtsi); in Kyiv only with shelter.

Location: light-demanding, requires good soil. Needs sites protected from cold winds; the plant should receive at least 6 hours of sunlight per day. An ideal spot is a south-facing wall of a house or fence; southeast or southwest aspects are also suitable. In open sites it generally does not flower. In maturity plants are drought- and heat-tolerant. Tolerates urban conditions well.

Soil: prefers light, well-drained, fertile soil; does not like very wet or calcareous soils.

Planting: recommended planting mix: topsoil, peat, humus and sand in a ratio of 3:1:1:1. Planting hole dimensions – 60×60×50 cm.

Care: requires a strong and reliable support, as well as regular tying of shoots. In winter the plant is removed from the support and laid on the ground for protection.

Pruning: to control growth, side shoots can be cut in mid-summer by 20–40 cm. Standard (single-trunk) forms can be created. Flowers form on older wood or on last year's shoots, as well as on short flowering shoots of the current year. For abundant flowering it is recommended to prune last year's shoots annually at the end of May to a length of no more than 30 cm. In August, shorten the current year's growth to 4–5 buds. Early in spring, after removing winter protection and tying to the support, shorten last year's growth by 2–3 buds.

Propagation: can be propagated by seed, but cultivar characteristics are not retained, and flowering is delayed and less abundant. Seeds are stored in bags in an unheated dry room. Viability under such conditions is 3–4 years. Field germination of seeds is 80%, laboratory – 90%. If not fully ripe, seeds rot quickly. Autumn sowing is done immediately after collection; spring sowing without stratification. Sowing depth 2–3 cm. Propagates well by layering and cuttings.

Pests: green aphid, clover mite, leafhoppers, caterpillars.

Diseases: bud pyriculariosis.

Companion plants: at the base of Chinese wisteria one can plant white (yellow) daffodils and dark-red Darwin hybrid tulips, dark-purple hyacinths, imperial fritillary, mezereon.

Uses: Used for decorating gazebos, pergolas, trellises, fences, houses, terraces, balconies and espalier structures. Can be grown indoors as a bonsai. Can also be grown in large pots and tubs in greenhouses and winter gardens.