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Welcome to our Head Gardener’s Journal

In this monthly column, we will share technical aspects of our work and also keep you up to date about ongoing projects. If there is any topic you might want to hear more about, please ask during your next visit!

Winter Pruning of Wisteria

One of the May highlights in the South Garden is when the large oak arbour is smothered in fragrant snow-white wisteria blooms. We grow two varieties: Wisteria brachybotrys ‘Shiro-kapitan’ and Wisteria sinensis ‘Alba’.

Wisteria racemes on the East Terrace arbour in mid-May

To achieve this sumptuous display, it is necessary to diligently prune the wisteria plants. This happens twice a year, in July-August and January-February. If left unpruned, wisterias will ramble and grow to immense size, but will not flower as profusely. Summer pruning improves the air circulation through the plant which is beneficial to plant health. It also allows more sunlight to reach the base of the shoots which encourages wood ripening and flower bud formation. The current year’s growth is pruned back to five or six leaves.

Winter pruning is carried out when the plant is leafless and dormant. It is more severe, reducing last year’s growth to two or three buds. This shapes the plant and ensures that the flowers will not be obscured by foliage.

Dormant wisteria plants congested with spindly shoots from the previous year
Last year’s shoots are pruned back to three leave nodes
After pruning, the plant is tidy and ready for the new season