The Pros and Cons of Planting an Empress Tree
The empress tree (Paulownia tomentosa), sometimes also known as the princess tree or Royal Paulownia, is not only adorned with lovely purple, vanilla-scented flowers and big beautiful, velvety leaves, but it also grows very quickly. For this reason, it is a popular choice to plant for quick shade. It is actually one of the fastest-growing trees in the world and has been known to grow up to 20 feet within its first year, so you'll be able to enjoy its beauty sooner than you might expect. As a bonus, its wood is very valuable. In fact, it's so valuable that people sometimes steal young empress trees in the dead of night.
The Empress Tree's Royal Roots
Named for Princess Anna Pavlovna, daughter of Czar Paul I, the empress tree is native to central and western China, where its wood has been used for more than a thousand years to make furniture, musical instruments, wood carvings, pots, bowls, and spoons. The Japanese also prize it highly as the perfect wood for making sandals (click to see some nice ones). Wood from empress trees is blond in color, very easy to work with, nearly as light as balsa but twice as strong, has a silky feel, and resists insects and decay. Nice empress trees with straight trunks can fetch thousands of dollars, which is why they're subject to thievery. Many people have gone to bed with thriving empress trees on their property, only to discover nothing more than stumps in the morning.
How to Care for Empress Trees
Empress trees are incredibly easy to grow. You will want to plant them in fertile, well-drained soil and give them ample water, especially if you are growing with the intention to sell their valuable wood. The soil should be more acidic than alkaline and preferably moist sandy-loam. Partial light shade is okay for this tree but it prefers to be in full sun, for at least six hours a day, in order for most of its flower buds to fully bloom—particularly because the flower buds are often damaged by early spring frosts. Typically, you can expect thousands of flowers to bloom on an empress tree in late April or early May, but if you are not opposed to having fewer flowers, more shade will not harm the tree. Conscientious pruning will be key to curbing your empress tree's rampant growth and keeping it to a manageable size. We recommend cutting it to around five feet tall when autumn comes.
Empress Tree Downsides
Even though they are very valuable and could potentially make you a fortune, I must let you know the unfortunate truth about empress trees. Much like catalpas, mulberry trees, and the tree-of-heaven (Ailanthus altissima), the empress tree belongs to a class of trees that some consider to be less-than-ideal. Not only does it seed all over creation, producing as many as two million seedlings per year, but it will also sometimes grow in absolutely terrible soil where few other trees will. You'll often see it growing on old mining sites, next to railroad tracks, out of cracks in the pavement, or on rocky cliffs. The trees pictured at the start of this article are growing on buried busted-up concrete rubble. If you cut an empress tree to the ground in spring, it is extremely likely that it will grow 10 feet within the next year and sprout gigantic leaves. Lack of cold-hardiness is one limitation, though. Flower buds are usually killed north of the Upper South (Zone 6).
Empress trees grow so rampantly that they are classified as a noxious weed in Connecticut, where sales of this species are actually banned, and classified as an invasive species in North Carolina. Planting an empress tree too close to a garden or other trees will often result in the empress hoarding nutrients and water from the nearby plants. If planted too close to a building, the roots have a strong potential to damage the foundation. Therefore, the empress tree is not recommended for landscaping. If you decide to add one to your property, it is imperative that you ensure that it has ample room to grow and is far enough away from any buildings and other plant life. It's also recommended that you do as much as possible to remove any stray seedlings that fall, or else you may have multiple empress trees sprouting in your yard. If that happens, be sure to uproot them long before they've had time to mature. You do not want a yard full of these giants, despite their beauty.