Reproduction of the Princess tree
Reproduction of the Princess tree
Princess tree (Paulownia tomentosa Steud., 1841) is a plant of the Scrophulariaceae family native to the boreal temperate areas and introduced in Europe in the first half of the nineteenth century for ornamental purposes.
Suitable breeding habitat –
Paulownia tomentosa is a deciduous tree erroneously attributed as native to central and western China.
It is an extremely fast growing tree with seeds that disperse easily and is an invasive exotic species in many countries such as in North America, where it has undergone naturalization in large areas of the eastern United States.
P. tomentosa has also been introduced in western and central Europe and is also establishing itself there as a naturalized species.
Princess tree belongs to a genus of plants that have inhabited the earth for hundreds of thousands of years and are native to the boreal temperate zone (Europe, North America and Asia). In Italy, in Pocapaglia – Piedmont, Paulownia fossils belonging to the Zanclean – Pliocene period have been found. A group of research, development and dissemination of this tree has thus started from Italy by an environmental organization called Paulownia Piemonte (and Paulownia 4Planet), which takes its name from the region where the most ancient fossil remains were found. never found.
The constant research has highlighted how the genera and the hybridization between them, has led to obtaining intervarietal hybrids more resistant to diseases and differentiation of the varieties to have hybrids more suitable for different contexts.
In Asia it has also been used for curative purposes for over a millennium; this fact created the false myth about its origin, erroneously related to China.
In Europe it soon spread to city parks.
Propagation –
For the reproduction of the Paulownia it must be taken into account that this plant needs a sunny or medium-sun position, loose and rich soil.
It easily naturalizes in environments characterized by habitats where mountain broad-leaved trees grow at altitudes between 1,300 and 2,000 meters.
The plant does not tolerate prolonged and late frosts.
In fact, the Paulownia tomentosa, although very resistant to cold, able to withstand temperatures up to about -25 ° C, however the younger plants, and in particular the seedlings under the age of 2 years, are much more resistant to frost, as well as the new spring shoots.
Propagation occurs by seed which is sown as soon as it is ripe in a cold environment where it usually germinates quickly.
It is advisable to sow the seed stored at the end of winter in a greenhouse at 15 – 20 ° C; furthermore the seed needs light for germination. The germination rate is good.
The young seedlings, barely manageable, are then placed in single pots and transplanted after the first winter, where they should be grown, possibly, in a protected area.
The transplant period is in late spring or early summer, after the last expected frosts.
It can also be propagated by cuttings of semi-mature wood, of 5 – 8 cm in the period of midsummer in a shady area. As usual, for the first winter, the plant should be kept in an area protected from the cold.
Another propagation system can be that through root cuttings, 4 cm long, to be carried out in the period of December; this method has a good rooting percentage.
Ecology –
Princess tree is able to adapt, grow and develop in poor soils. It is an ideal tree for the improvement and reclamation of poor and polluted land; moreover it grows on soils polluted mainly by heavy metals and harmful substances, where other trees do not survive.
By absorbing these substances, it frees the soil and lays the foundations for a subsequent reforestation phase.
The huge Paulownia leaves reach 50-70cm in diameter. After the fall they not only fertilize, but also restructure the soil with natural humus. In this way, they ensure the necessary conditions for the growth of the species grown together with Paulownia or later.
Paulownia is also a favorite tree species also in the fight against erosion. In addition to purifying the soil and the water contained in it, it frees the air from harmful gases, which are often found in unacceptably high concentrations, especially in large industrial cities. Paulownia absorbs 10 times more CO2 than any other tree species, releasing large amounts of O2.
From an ecological point of view, the use of Paulownia for biomass is important, however it is an invasive plant in many natural areas including forests, roadsides and river banks, so its introduction must be carefully evaluated and monitored.