This time of year, there's a tree that blooms with lilac colored flowers that can be seen here and there along I-270 between Gaithersburg and D.C. Does anyone happen to know what kind of tree that is?

-- Mary N. Macdonald (mnmacd@his.com), May 11, 2004

Answers

The tree is called Royal Paulownia (Paulownia tomentosa) also called Empress Tree or Princess Tree. It is an invasive species (from China) and not native to Maryland, DC, Virginia, etc., but is unfortunately now growing wild from New York to Georgia.

Michael Dirr, noted woody plant expert, author, and professor at the University of Georgia writes: "In the standard frame of reference for shade trees, Paulownia tomentosa is a total loser....The dark green leaves...have the endearing characteristic of shedding in summer....For residential landscapes, the species has few redeeming qualities."

The tree was obviously introduced to this country as an ornamental due to the lovely purple flowers that look like foxgloves. Unfortunately, each tree produces millions of seeds, which are populating our woodlands and out-competing our native species. I recently received an advertisement for Paulownia, boasting that it would grow up to ten feet a year, which is true! This is a nasty species for the mid-Atlantic (comparable to the Kudzu vine that now covers 7 million acres of the Southeastern US) and should be avoided at all costs. I don't even think you could buy one at any reputable nursery.

In summary, many other better choices exist for shade tree planting.

-- Genie Tillisch (genielt@starpower.net), May 11, 2004.