Wisteria macrostachya Aunt Dee

Wisteria macrostachya (or frutescens) 'Aunt Dee' is a vigorous Kentucky wisteria with light lilac-blue flowers, renowned for its unparalleled hardiness. Its particularly dense clusters of flowers exude a sweet, pleasant grape-like scent. This climber, slightly less invasive than its Asian cousins, blooms in June, among foliage that is darker and shinier than that of Chinese and Japanese wisterias. Finally, like most American wisterias, this species blooms from a young age and turns dark yellow in autumn.

The 'Aunt Dee' American wisteria is a horticultural selection derived from Wisteria frutescens subsp. macrostachya. It is a woody, deciduous climbing plant belonging to the large Fabaceae family, like clover, alfalfa, and lupins. The subspecies macrostachya, which is more northern than the type species, is native to a geographical area ranging from southern Missouri and Illinois to eastern Kentucky in the north. It can be found in moist forests and along watercourses. Its long, twining stems, slightly less vigorous than those of Chinese wisteria, are hairy when young and quickly lignify. It is a plant that is not very demanding in terms of soil (although it dislikes active limestone) and can grow in soils that are occasionally waterlogged or, conversely, poor and fairly dry in summer, if they are deep. This species is considered more cold-resistant than Asian wisterias, not because of the hardiness of the plant itself, but because its flower buds do not form in summer, but in spring on new wood, thus escaping very harsh winters.

The stems of 'Aunt Dee' Wisteria can easily reach 5-6 m in length, winding spontaneously around supports, in a counterclockwise direction. The growth of new shoots is very rapid, reaching 1 to 2 m in a single season in cool soil. The flowering of this variety takes place in June, more or less early depending on the climate, on relatively young plants. It develops among already well-developed foliage. Long clusters, measuring 25-30 cm, contain up to 50 small papilionaceous flowers in a blue-mauve colour, emitting a pleasant fragrance in calm weather. They open from the base to the tip of the cluster. The plant sometimes sporadically reblooms during the summer. The young leaves, tinged with bronze, then turn a slightly shiny dark green before becoming ochre yellow in autumn and falling. They are 10 to 30 cm long and divided into 9 to 15 ovate leaflets, giving the foliage a light appearance. Very long-lasting, Aunt Dee Kentucky Wisteria can live for more than 30 years. Its flowering is nectar-rich and attractive to bees. The fruit is a flattened pod, 5 to 10 cm long, brown, which persists until winter. It contains numerous small brown kidney-shaped seeds.

Aunt Dee Wisteria is preferred over any other variety in regions with long, very cold winters. This romantic plant can enhance a facade or structure, no matter how modest. It is particularly useful for covering a wall or unsightly fence, winding around any sufficiently sturdy support. Prefer a solitary position, in full sun or partial shade in hot climates. Alternatively, associate it with vigorous climbers such as  Clematis montana, a trumpet creeper, or an aristolochia. With patient and regular pruning, this climber will become a beautiful small tree that can be prominently placed in the garden.

However, be patient: the first flowering of Wisteria may not appear for 2 to 3 years, depending on the growing conditions and the age of the plant you purchase.