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Common Name:

Royal Paulownia or Empress Tree

Scientific Name:

Paulownia tomentosa

Family Name:

Scrophulariaceae (sometimes placed in the Bignoniaceae)

Description:

Royal Paulownia is a medium size deciduous tree with an irregular crown 30 ft to 40 ft tall in our region. In its native land it has a larger forest tree habit. It has naturalized in the Southern US. Trees have large pubescent heart-shaped leaves and very coarse textured stems. Plants appear tropical in effect in summer, but are a liability in winter landscapes. The light purple to violet colored foxglove-like flowers appear in spring. Trees are weak-wooded and messy. Serves similar purposes as Southern Catalpa.

Plant Habit or Use:

Tree, medium tree, large tree

Exposure:

sun

Flower Color:

Light purple to violet outside, light purple to white with a yellow strip inside, borne from pendent spherical overwintering buds

Blooming Period:

Spring

Fruit Characteristics:

Capsule, not showy

Height:

30 ft to 40 ft here, taller in native land

Width:

30 ft to 40 ft

Earth–Kind® Index:

  • Heat Tolerance: High Heat Tolerance
  • Water Requirements: Medium Water Use
  • Soil Requirements: Medium Soil Requirements
  • Pest Tolerance: Medium Pest Resistance
  • Fertility Requirements: Low Fertility Requirements
Explanation of the Earth–Kind® Index breakdown

Firewise Index

7.00
Explanation of the Firewise Index numerical value

USDA Hardiness Zones:

6, 7, 8, 9

Regions that intersect these hardiness zones:
Region A - Panhandle and High Plains Region B - North and Central Texas Region C - Northeast and East Texas Region D - West Texas Region E - Upper Rio Grande Region F - Hill Country and Central Coast Region G - Southeast Texas Region H - Rio Grande Valley
Click image for enlarged map of USDA Hardiness Zones

Additional Comments:

Heat, salt, and pllution tolerant, but prone to wind damage. Marginal ornamental assets.
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A Special Note about Cool Season Annuals

Cool season annuals typically are planted in the fall or early winter and flower in early spring under moderate temperatures. This group of plant materials includes: pansies, snapdragons, violas, dianthus, flowering cabbage/kale, etc. Because cool season annuals flower in the spring when conditions are mild, most have limited heat tolerance.

As a result cool season annuals do not receive a high Earth–Kind® index despite their outstanding landscape qualities.