Common Name: Foxglove Tree

General Information

Paulownia tomentosa is a deciduous tree with a broad, round-topped crown and a rather open habit; it can grow up to 20 metres tall. The bole can be around 100cm in diameter[, , ].
The tree is harvested from the wild for local use as a medicine, source of materials and sometimes as a food. A fast-growing tree with a good quality timber, it is harvested commercially and is also grown for its wood and as a soil stabilizer and restorer. The tree is very often grown as an ornamental.
Paulownia tomentosa is a showy, aggressive ornamental tree that is also grown in plantations for timber production. It has tended to escape from cultivation and invade disturbed areas. It can invade rapidly after disturbances such as fire, construction or floods, and its ability to resprout prolifically allows it to survive fire, cutting, and even bulldozing on building sites. It seeds profusely and resprouts from roots and stumps, often forming monocultures, and is proving to be a problem weed in eastern USA. It continues to be promoted, however, in North America and elsewhere, and it is possible that it could prove invasive in Europe where it continues to be introduced and planted[].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - central and eastern China.

Habitat

Deciduous montane woodland; at elevations from 1,300 - 2,000 metres[, ].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	15.00 m
Growth Rate	Fast
Pollinators	Insects
Self-fertile	Yes
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Paulownia tomentosa is a very cold-hardy plant, able to tolerate temperatures down to around -25°c when the wood has been fully ripened. It grows best in areas with hot summers - in areas with cooler summers (even if the winters are mild), such as the maritime regions of the temperate zone, it often grows poorly, failing to properly ripen its wood and suffering frost damage over the winter[, ]. Younger plants, and especially seedlings less than 2 years old, are much more frost tender, as is the new growth in the spring[, ].
Prefers a deep moderately fertile moisture retentive but well-drained soil in a sunny sheltered position[, ]. Plants are very susceptible to waterlogging of the soil, and can die within 5 days if the ground is flooded[]. Succeeds in poor soils and in highly acid conditions[]. Prefers a pH in the range 5.5 - 7, tolerating 4.5 - 8[]. Plants are tolerant of atmospheric pollution[]. Established plants are drought tolerant[].
A very ornamental and fast growing plant[].
Trees can reach a mean height of 15 metres with a mean diameter of the bole around 30 cm within 10 years of planting[].
Annual wood production potential is 25 - 35 cubic metres per hectare[].
Trees are very amenable to coppicing[]. They can be coppiced annually, when they will then produce very vigorous growth that can reach more than 5 metres tall with large leaves that can be up to 1 metre wide[].
The flower buds are formed in autumn and can be excited into premature growth during mild winter weather, this growth is then more susceptible to frost damage[, ]. The flower buds are hardy to about -15°c when dormant[]. Plants do not flower reliably in maritime zones, this is probably due to insufficient warmth and dryness in the summer[].
Branches tend to be brittle[].
The flowers have a delicate sweet fragrance[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

Leaves - cooked. An emergency food, used when all else fails[, ].

Flowers[]. Eaten with miso[].

Medicinal

A decoction of the leaves is used to wash foul ulcers and is also said to promote the growth of hair and prevent greying[, ]. The leaves are also poulticed onto bruises[]. The leaf juice is used in the treatment of warts[, ].

The flowers are used in the treatment of skin ailments[, ].

A tincture of the inner bark is used in the treatment of fevers and delirium[]. It is astringent and vermifuge[, ].

Agroforestry Uses:

Paulownia tomentosa is fast-growwing, has an extensive root system, and is tolerant of drought, poor soils and very acid conditions. It is used in soil stabilization projects and also in soil reclamation projects on land polluted by mine waste etc[, ].
The tree is suited for intercropping with wheat, cotton and maize, the resulting yields of wheat have been measured to 16% higher, those of cotton 7% higher, and those of maize more than 11% higher than those from plots without the tree[]. The roots of trees grown from seed occupy a different layer than most annual crops and this suggests its potential for intercropping. However when propagated by cuttings, the tree forms an extensive lateral root system and loses its deep rooting characteristics[].
The tree is a natural pioneer species, colonizing disturbed areas such as roadsides, mined areas, sanitary landfills, abandoned agricultural soils, and deep, moist but well-drained alluvial soils along waterways. It can be used in reforestation projects and for establishing woodland gardens[, ].
The flowers are a good forage for bees, producing a good quality honey.

Other Uses

An extract of the leaves, flowers and bark is used as an ingredient in commercial cosmetic preparations as an astringent, emollient, hair conditioner and skin conditioner[].
An extract of the leaves is used as an ingredient in commercial cosmetic preparations as an astringent, emollient, hair conditioner and skin conditioner[].
An extract of the wood is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].

A good quality, lightweight timber, the reddish-brown wood is comparatively soft and has a beautiful grain[]. It is not generally attacked by insects. It is used for making delicate furniture, cabinets, musical instruments etc, is a good wood for carving, and is also used for items such as boxes, clogs, floats and general wood work. It is used in construction, being good for posts and beams[, , , , ].
With its rapid early growth, the tree is a good source of pulp for the paper industry[].
A source of charcoal[, ]. The wood yields an excellent charcoal that can be used for high class fireworks and gunpowder[].

Propagation

Seed - best sown as soon as it is ripe in a cold frame - it will usually germinate rapidly[, ]. Sow stored seed in late winter in a greenhouse at 15 - 20°c[]. The seed requires light for germination[]. Fair to good germination. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, 5 - 8cm with a heel, mid summer in a frame. Overwinter in a cold frame for its first year and plant out in late spring[].
Root cuttings 4cm long in December. Good percentage[].