Wisterias are deciduous, twining climbers, native to China, Japan and the eastern United States. Of the ten species the three most commonly grown are Wisteria floribunda (Japanese wisteria), W. sinensis (Chinese wisteria) and W. brachybotrys (silky wisteria), and their cultivars. All three species are strong-growing and are capable of reaching a height of around 10m (30ft) in trees or a spread of up to 20m (60ft) or more against a wall.
Wisterias flower in the spring with occasional summer flowers. Most begin flowering within 3-4 years of planting. After a long summer, established wisterias may form pendant, bean-like seedpods that are an additional feature.
Wisteria prefers a sunny position, but can be grown in slight shade. Plant in a well-drained, fertile soil.
If buying a new wisteria, always choose one that has been grown from cuttings or by grafting. Seed raised wisterias flower less reliably, and also take longer to flower. Grafted plants can be detected by the visible bulge of the graft union near the base of the stem. Named cultivars are almost always grafted, whereas species plants may not be.
Plants will dry out quickly, especially in a light or sandy soil, so keep plants well watered, particularly when newly planted and during dry periods.
Feed in the spring, with Growmore or Fish, Blood and Bone at the rate recommended on the packet. In sandy soils (which may have low potassium levels), also apply sulphate of potash at 20g per sq m (1/2oz per sq yd). You could also use rose or flowering shrub fertilisers.
Wisterias are usually thought of as climbers, but you can grow wisterias in containers, and train as a free-standing standard. This is particularly suitable for a small garden.
Use a quality loam-based potting compost such as John Innes No 3. Containerised wisterias can be fed with liquid tomato fertiliser, Phostrogen, Miracle-gro or similar flowering plant foods. Mixing controlled release fertiliser granules into the compost is another alternative.