Ask Mr. Smarty Plants

Late winter is a good time to plant Texas (American) wisteria (Wisteria frutescens). Early spring will be fine as well.

American wisteria is a high-climbing woody, deciduous vine, 25-30 ft. long. Shiny, dark-green, pinnately compound leaves bear 9-15 leaflets which are opposite on the leaf stem, with 1 leaflet at the tip. The flowers are in large, drooping clusters 6–9 inches long that appear after the plant has leafed out, a difference from the popular Asian species.

American wisteria is often used as an ornamental planting and has probably escaped from cultivation in many locations. In Texas, the Dam B cultivar has blue flowers in racemes and flowers late May to June and sporadically throughout the summer and fall. A cultivar called Nivea has white flowers.

The blooms only appear on new wood. Individual flowers are nearly 1 inch long and are lilac or bluish purple and quite fragrant. A brown, bean-like pod persists until winter. This species is less aggressive than the similar Asian species. Prefers a good loamy soil in a sunny south or southwest facing position, sheltered from cold winds and from early morning sun on frosty mornings. Plants can become chlorotic on alkaline soils. Prefers a rich soil, but some gardeners feel too rich a soil results in too much leaf growth. Tolerates seasonal flooding.