Paulownia trees

Description

Paulownia trees, Foxglove trees, Empress trees

Hardy:	Varies with variety, though the consensus is that all varieties of Paulownia trees will survive  -10℃ with ease.
Soil:	Will tolerate a wide range of soil types, though prefer deep well drained sandy soils.
Growth:	Exceptional, up to 3m per year
Height:	Up to 30m plus
Biomass:	Good firewood, can be coppiced, pollarded or logged
Lumber:	Paulownia timber is high value with various uses
Wildlife:	An abundance of early flowers for bees and insects

Exceptionally fast growing and provide an abundance of flowers in early spring before the leaves develop. The flowers resemble foxgloves, and Paulownia trees have several names, including “Foxglove Tree” Easy to see why !

Photo by Kronelia

I’ve done a fair amount of research into when you can expect your Paulownia tree to flower with mixed results. One nursery says theirs flower from year three onwards.
Those I have seen in West Clare, Ireland, had masses of purple / blue flowers this year 2020, which wasn’t a particularly severe one so far as frosts were concerned, though there were several severe storms and gales. They are mature, over ten years old, though as I say, an abundance of purple flowers.

Paulownia trees would be a good choice for bee keepers with it’s early flowering.

Paulownia is a very popular tree grown by enthusiasts for their flowers and also their leaves, which depending on how the tree is cultivated can be up to thirty centimetres across.

Photo by Wendy Culter

The protein rich leaves are also used as animal fodder.

There are several varieties, the five I have for sale are:

• Tomentosa; is the most popular amongst gardening enthusiasts for the attractive floral display, the impressively large leaves and abundance of purple flowers.
• Shan Tong; is grown more commercially for its timber which is highly prised for its toughness and lightness. Used for making surfboards, guitars and other musical instruments as well as furniture. It is a cross between Tomentosa (for growth rate) and Fortunei for the narrow crown and quality of the timber.
• Pao tong; is considered to be amongst the most frost hardy, though I note frost tolerance is only an issue in Eastern European countries where temperatures regularly dip below -20℃. Paulownia Pao tong is also grown commercially for timber as with Shan Tong and is also a hybrid.
• Nord Max 21; it seems every time I buy Paulownia seed there is a new hybrid variety, though this is a good thing, especially if you are a commercial grower, or a small holder growing for firewood. Faster straighter growth for either commercial timber or easily processed logs for firewood.
• Elongata; is a natural variety. Like Tomentosa it is considered good for bees because of the abundance of flowers in early spring.

NOTE all five varieties will provide good commercial timber. A technical cut as it is called down to 2cm from the base and pruning is required to ensure straight trees without branching.

I like the open easy to walk though understory created by these deciduous trees. In winter when the leaves have fallen, a landscape not dissimilar to a beech forest.

Photo by Hooked on Light

I definitely want to promote agro-forestry here in Ireland and Paulownia are a forestry tree that lends itself to this. Indeed it is considered to be one of the most profitable uses of land, even if you only have a small area and keep a few chickens.

Photo by Brian Bornstein

Paulownia trees are grown for biomass and they make good general firewood for the home stove or fire.

In the Chinese province of HangZhou shelter belts were planted primarily with Paulownia. The Argoforestry improved crop yields tenfold 😮
Wind speeds were reduced by up to 40%, summer air temperatures by up to 1.3℃, winter and autumn air temperatures increased by up to 1℃, evaporation decreased by up to 25%. Remarkable !
With expected increases in extreme weather events, shelter from severe Atlantic storms is definitely a consideration here in Ireland and with recent heat waves, moderating temperature and evaporation, even here in Ireland is worth consideration.
What farmer, whether livestock or tillage wouldn’t like to improve their yields.
Farm Forestry New Zealand

Paulownia plays a key role in agroforestry in China especially as shelter belt, though their usefulness also extends to a variety of uses including fish meal in integrated permaculture systems. This before they are harvested for their valuable timber usually before they are ten years old; a comparatively rapid return on investment.

NOTE I currently, mid 2021, consider Paulownia to be an experimental forestry tree for Ireland, though I have planted my personal experimental forest 😉

Other names for Paulownia trees include Empress tree, and in Japan they are know as Kiri, which specifically refers to the Tomentosa variety. Tomentosa grow rapidly, up to three metres a year, though they can be pruned and cut right back. If you do cut Tomentosa back to the base it encourages the leaves to become even larger; thirty centimetres across or more.

The variety Shan Tong is a hybrid, bred for even faster growth. In its native, ideal habitat, mostly south east Asia they can grow at six metres a year. Probably a more realistic growth rate here in Ireland would be two, possibly three metres a year. Still very impressive 😮

Paulownia trees have exacting requirements when it comes to hydration. They like a lot of it, but don’t like having their roots soaking in water constantly. So this isn’t a tree for the bog. It is however suited to Ireland as it can adapt to a wide range of temperatures and is frost hardy. It’s also happy in variable PH levels.
It will prefer free draining soil, avoid planting it in heavy clays or rocky ground. By that I would think impermeable bed rock. Though I note there are several Paulownia Tomentosa growing happily on stony ground here in West Clare. Like most lifeforms, Paulownia are will adapt to their environments.
With growth rates of three metres plus a year, it’s definitely worth experimenting There’s an interesting growth projection in the following link Paulownia Trees Europe.