Paulownia tomentosa, a deciduous tree also known as princess tree or foxglove tree, produces huge green leaves and clusters of aromatic lavender flowers in spring. Hardy in USDA hardiness zones 5 through 8, the tree has escaped cultivation and naturalised in many areas of the country. A fast-growing tree, Paulownia tomentosa can reach up to 12 feet tall in a single season with proper care. Gardeners value the tree for its ornamental appeal and ease of care. Commercial growers prize Paulownia tomentosa for its valuable wood that is used to make furniture and other goods in Japan.
Select a planting location that has average, well-draining soil, receives full sunlight and provides protection from strong winds. Paulownia tomentosa may tolerate light shade for part of the day but generally does not perform well in shaded areas.
Plant Paulownia tomentosa in early spring after the ground is workable and the danger of frost has passed. Dig a hole three times wider than the root ball and of equal depth. Place the roots into the hole, backfill with soil, and tamp down the soil around the tree with your hands.
Water the tree once every 10 to 14 days, allowing the soil to dry out slightly between applications. Increase watering to once or twice a week when temperatures rise above 35 degrees Celsius. Paulownia tomentosa is moderately drought tolerant but performs best when provided with water when the soil becomes dry.
Spread a layer of organic compost over the ground around your Paulownia tomentosa tree once annually in early spring, before new growth begins. This helps the soil retain moisture throughout the growing season and provides nutrients. No supplemental fertilisation is required.
Prune the plant back to one bud from the ground during late winter if desired. This dormant season hard pruning increases the size of the tree's leaves and encourage a more shrublike growth habit, but it also prevents flowering. If you desire flowers, do not prune.
If your Paulownia tomentosa tree is located in a woodland garden, mulch with pine needles or leaves instead of compost for a more natural appearance. Grow Paulownia tomentosa in a container as a foliage plant if desired. Fill the container with well-draining, all-purpose potting soil, place in full sun, and water about once a week. Fertilise once a year in spring with a balanced fertiliser to promote vigorous foliage growth.