Two Purple Flowering, Fragrant, and Aggressive Plants

On a warm day, sun shining, breeze barely lifting newly sprung leaves, the tantalizing purple odor drifts into our windows or catches in our noses as we walk through neighborhoods or city streets.

Is it a tree? A vine? A bit confusing but actually two very separate plants that share a lovely shade of purple, noticeable fragrance, and sadly both are considered invasive.


Flowering Wisteria vine. Photo courtesy of S. Lee

The purple-flowering vine is probably Wisteria, known commonly and botanically by the same name. In the legume family, this woody climbing vine was introduced to the eastern United States from China and Japan, and is almost as ubiquitous as kudzu in some area of the south east. However, its reputation is a notch or two above that of kudzu, and while it can twine around tree trunks and branches tightly enough to strangle, it also appears in our landscapes as a religiously controlled Wisteria ‘tree’. Although there is a native version of Wisteria, American Wisteria or W. frutescens that is better behaved, non-native versions are more often planted in our landscapes primarily because their blooms are bigger and showier. But a plus for our native species is that it attracts butterflies, serving as a host plant for the silver spotted and long-tail skipper larvae. Even growing our native species, it needs to be pruned and kept in check.

More fragrant varieties include ‘Black Dragon’, ‘Texas White’ (yes blooms are that color), ‘Longissima’’, “Pink Ice”, “Caroline” (highly fragrant), and “Prematura” ; a few selections that grow in this area.

princess tree

Purple flowering Princess Tree (Paulownia tomentosa). Photo by Irina Afonskaya/Shutterstock

Not in the mood for a vine but like the thought of a purple-flowering tree? Check out the Princess Tree (or Paulownia tomentosa) growing vigorously beside the 1st Ave. North viaduct in downtown Birmingham on Sloss Furnaces property. Also listed on “invasive” plant lists for Alabama, the recommendation is to refrain from planting additional species as it spreads rapidly enough from seeds. Highly prized in Japan for its wood, in this area it is a ‘survivor’ tree, able to grow and reproduce on roadsides (check I-459), disturbed habitats, and landslides. The problem with its adaptability is that it ‘adapts’ right over our native trees, bullying its way into ecological niches where it can out-compete rare native plants.

However, when the Princess tree’s large, showy, fragrant (smells like bubble gum to some) upright-clustered blooms pop out in late March – May before its large leaves unfold, most comments fall into the ‘I-gotta-have-one-of-those’ categories.

Due to its popularity in Japan, the Princess tree is grown in plantations through the southeast for export purposes.

These are popular plants but behave aggressively in our area, are considered invasive, and could create more problems than they’re worth if inadvertently planted in our landscapes or gardens.

By Sallie Lee, Urban Regional Extension Agent, Alabama Cooperative Extension System.  Contact Sallie at

The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce.  Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.

More on Wisteria

Alabama Extension

The Alabama Cooperative Extension System operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities and answers home-gardeners' questions each week on Birmingham Gardening Today.

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