Plants grown from seeds start flowering in the 8th to 12th year after planting and flowers may be scarce.
Plants propagated from stem cuttings can, depending on a variety, start blooming in the 2nd to 7th year after planting and will flower very profusely. During the first 3-4 years wisteria grows slowly and it needs careful nurturing and screening in winter. Afterwards it starts growing vigorously with 1-2 m of annual growth and attains a height of 10 m and more. It has twining stems that twist round the supports and its roots can spread at a distance of over a dozen meters from the plant. During harsh winters it may freeze, but new stems will emerge from the roots. It will grow and flower best in a warm and sunny, sheltered position, in moderately fertile and moderately moist soil.
Pruning can reduce the growth of wisteria and speed up and enhance blooming. During the first 2-3 years the plant should be left to grow freely to allow it to strengthen. Then you should cut it back hard, in a similar fashion to vine, in order to encourage the formation of the flower buds. Flower buds are formed in early autumn so the basic pruning is best done in summer (at the end of July). Cut the majority of the stems above the 4th leaf, leaving untouched only the stems that are needed to shape the plant. In early spring you can touch it up, cutting off all the stems that are too slim, unneeded or dead, and leaving only 2-3 buds on the lateral stems. Cover all pruning cuts with a pruning paste e.g. Santar or Funaben. You can make this paste on your own by adding the fungicide to undiluted emulsion paint, in the dose of 20 g to 1 l. If despite the pruning of the stems, after many years wisteria will not star blooming, it's advisable to cut roots, as this may encourage flowering in the following year. Roots should be cut in spring (March), by digging a spade as deep as it's possible round the plant at a distance of 1,5-2 m from it.
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Wisteria floribunda - Japanese Wisteria has left-hand stems:
- 'Honbeni' - pink flowers in long racemes,
- 'Ludwik Lawin' - violet flowers,
- 'Multijuga' - violetblue flowers gathered in exceptionally long racemes,
- 'Shiro-noda' - white flowers in long racemes,
- 'Violacea Plena' - double purple flowers.
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Wisteria sinensis - Chinese Wisteria, has right-hand stems and blue flowers:
- 'Amethyst' - purple blooms in long racemes;
- 'Blue Sapphire' - blue flowers;
- 'Prolific' - pleasant smelling blue flowers appear already in the second-third year after planting.
- 'Texas White' - white flowers,