Will Growing a Royal Paulownia Tree Close to a Septic System Cause Harm?

Mature Size

• Paulownia tomentosa, commonly called Royal Paulownia, Royal Empress or princess tree, is a fast growing tree. It will commonly grow more than 2 feet per year to a mature height and canopy width of 30 to 40 feet; however, it can grow to as tall as 60 feet. The root system on this tree can be between 120 and 180 feet in diameter at maturity.

Native Status

• The Royal Paulownia tree is not native to the United States but has naturalized. This China native was introduced into the United States in the 1840s. Since then it has spread throughout the south-central and eastern third of the United States. It is commonly found growing along roads, streams and outer edges of wooded areas.

Invasive Potential

• In addition to growing quickly, Royal Paulownias spread aggressively by root suckering and seed dispersal. It is listed with the USDA as an invasive and noxious weed in Tennessee and is banned in Connecticut. Check with the local Extension office prior to planting this tree. The species is not considered invasive in all areas. There are also sterile hybrids available such as Empress Splendor. Sterile hybrids cannot reproduce by seed, although they may still spread by sending up root suckers. Control root suckers by simply removing them as they appear.

Planting

• Plant Royal Paulownia trees at least 40 feet away from the septic system. This should give the tree plenty of room to send out roots without becoming destructive. They should also be planted at least 12 feet away from underground utility lines as the roots can interfere with them as well. Plant it at least 15 to 20 feet away from the house or other buildings so that it can develop a healthy, well-expanded root system. A large, healthy root system gives it more stability to withstand inclement weather. Giving the tree 15 to 20 feet to expand, which is half of the diameter of the empress tree's mature canopy, also prevents damage to structures from limbs and allows the tree to grow freely into its natural shape.