Wisteria frutescens Longwood Purple

Wisteria frutescens 'Longwood Purple' is a recent variety of American wisteria, appreciated for its moderate growth and its willingness to flower even when very young. This attractive climbing plant blooms abundantly in late spring, after Chinese or Japanese wisterias, and then again in successive waves from late summer to autumn. Its clusters of flowers are denser and more robust than those of its Chinese cousin. They are a beautiful deep mauve-violet shade. They are also slightly less fragrant than their cousins. Wisteria spontaneously wrap their long voluble stems around railings, fences, arbours, and pergolas. 'Longwood Purple' is easier to integrate in small spaces. It will delight impatient gardeners who can admire its beautiful flowering often from the first year.

Wisteria frutescens is a woody climbing plant from the large Fabaceae family, just like clover, alfalfa, and lupins. It is native to the humid forests and riverbanks of the southeastern United States, from Virginia to Texas, from Florida in the south to New York in the north. Its long voluble stems, which are limited to a size twice smaller than those of Chinese Wisteria, lignify with age. It is perfectly resistant to cold, and undemanding in terms of soil (although it fears excess active limestone). It can grow in soils that are occasionally saturated with water. On the other hand, it can grow in poor soils that are dry in summer if they are deep enough.

The 'Longwood Purple' variety, selected in the famous Longwood Gardens in Pennsylvania, resembles the 'Amethyst Falls' cultivar. With the same compact growth, it distinguishes itself by its more colourful flower clusters. Its stems, which reach 4 to 5m (13 to 16ft), turn around supports spontaneously in an anti-clockwise direction. The growth of new shoots is very rapid, with about 1 to 2m (3 to 7ft) in one season in moist soil. The main flowering of this variety takes place in May-June, on very young plants. It can be early or late, depending on the climate. It develops on almost bare branches located near the main lignified stems. It bears long clusters measuring 10cm (4in), composed of small violet-coloured papilionaceous flowers tightly packed together. They spread a delicate scent in calm weather. They open from the base to the tip of the cluster. The plant reblooms at the end of summer, if pruned well. Young bronze leaves appear at the end of flowering and then take on a light green colour, turning yellow in autumn. They are 10 to 30cm (4 to 12in) long and divided into 9 to 15 rounded leaflets, giving the foliage a light appearance. It can live well over 50 years.

Wisteria 'Longwood Purple' is the epitome of romantic plants. Less imposing than its Chinese cousin, it can still enhance a facade or any small structure, no matter how modest. This lively plant will often outlive the person who planted it. Its compact silhouette will dress up a wall or cover an unsightly fence. It wraps itself around a trellis without restraint if left to its own devices. It tends to suffocate nearby plants. Give it a solitary location, in full sun or partial shade in hot climates. Alternatively, plant it with honeysuckles, passionflowers, and clematis. 'Longwood Purple', like 'Amethyst Falls', is highly appreciated by Bonsai enthusiasts. It can easily be trained as a small tree, transforming into a fountain of violet clusters in spring. If watered and regularly fertilised, it can live for many years on a patio or balcony, planted in a sufficiently large container.