NEW PALTZ, N.Y. — Although I haven’t seen a paulownia for years, I vividly remember one that bordered a path along which I used to jog when I lived further south, in Maryland. The tree caught my attention for its leaves. It was not their colour — green — that caught my eye, nor their heart shape. Outstanding about these leaves was their size: each was 2 to 3 feet across!
The whole tree was nothing more than a few vigorous, upright shoots growing 15 feet or so high. Over the years that I watched this tree, it never grew taller than that because someone’s pruning shears kept lopping it back near ground level. That 15 feet of growth was always made in a single season.
Another name for paulownia is empress tree or princess tree, because the genus was named in honour of Anna Paulowna, daughter of Tsar Paul I of Russia.
I would have guessed the name reflected the regal and frilly flowers. They appear over a period of a few weeks before the leaves unfold, and are arranged in upright, foot-long panicles like those of catalpa or horse chestnut. Paulownia’s flowers are lilac blue, with darker blue spots and streaks of yellow on the inside, somewhat like foxgloves or gloxinias. They have a vanilla scent.
I never did get to see or smell the flowers on “my” paulownia in Maryland. With its shoots lopped back each year, the stems never got old enough to make flowers. On the other hand, once a paulownia settles into maturity and begins flowering, its leaves grow large but not humongous.
GROW IT FOR ITS LEAVES, FLOWERS, OR WOOD
Some people grow paulownia as an ornamental foliage tree rather than for the flowers. The flower buds are generally killed below zero degrees Fahrenheit, so in northern regions you can’t count on getting flowers anyway. Below about minus 10 degrees Fahrenheit, even the stems are not hardy, so you get dieback and then only juvenile, humongous-leaved growth each year. Roots, especially of mulched plants, can survive up into Canada.
Further south is where paulownia can grow large and flower. As you might guess, here is a tree with lumber potential. In fact, paulownia is a valuable wood that has been used for centuries in its native Asia, so much so that it has been harvested to extinction in Japan. Large trees have even been spirited away by nightfall here in the U.S.
Paulownia wood is light and easy to work, yet strong with little tendency to warp, crack or split, even with changes in moisture. It has been used to make, among other things, furniture and musical instruments.
Despite the qualities of the wood and the attraction of the leaves and flowers, paulownias are sometimes looked down on as invasive plants. In fact, the tree is banned in some states. True, each seed capsule might release a couple thousand fuzzy seeds (once used as packing materials), adding up to as much as 20 million from a single large tree. True also that the trees pop up along road cuts or in cracks in abandoned parking lots. Paulownia is not really a fierce competitor though, and is easily choked out by other “weeds.”
Paulownia could get a bad name from its frequent promotion as a “wonder tree” in Sunday newspaper advertising supplements. No, it won’t grow 15 feet every year — only when it’s young. No, it doesn’t flower all summer — just two to four weeks early in the season. Yes, it does make shade, but very dense shade, often too dense for lawn beneath it.
So enjoy paulownia if you happen upon one; know its qualities and limitations before you plant one.