Conditions for optimal growth

As already mentioned in another section of our site, paulownia is a tree that easily adapts to very different soils and climatic conditions. However, this adaptability must not lead to erroneous evaluations when deciding to start a plantation for commercial purposes. If on the one hand, in fact, there are paulownia trees that thrive in very hot or very cold areas, and in soils that can be very sandy or clayey, this should not lead the investor to believe that in any climate o Soil a paulownia plantation can grow under conditions that ensure adequate growth rates, timber quality and profitability.

 

For this reason, we briefly report below what are the optimal conditions for a plantation, and those in the presence of which it is not recommended to start growing paulownia for commercial purposes.

 

Temperatures - several paulownia hybrids can survive in temperatures ranging from -30 to +45 degrees celsius; however, it must be taken into account that at temperatures well below 0 for prolonged periods, the plant, although it does not die, if it does not reach a certain degree of lignification on the trunk, risks that it burns, forcing a technical cut at the base at the end of winter. As for very high temperatures, even in these cases the plant survives, but in the warmer periods it will have a slower growth rate.

 

PH - as for PH, paulownia grows in good conditions between 5.5 and 8

Salinity - the degree of salinity must be less than 1%

Porosity - soils with porosity below 50% should be avoided

 

Soil texture - paulownia grows very quickly in light, well-draining soils; for this reason the ideal soils are those that have a low clay content (not exceeding 20-25%) and a good sand content. The plant suffers from water stagnation on the root system, and therefore, considering the high water requirement, it is essential that the soil is well draining. For this reason, soils with the presence of gravel or small and medium-sized stones are also suitable.

 

Depth of the soil - in consideration of the root system that the plant develops, it is important that the soil is deep, and that at least in the first 3 meters of depth there are no aquifers or rocky banks.

 

Swampy areas and stagnant waters - as already mentioned, paulownia suffers from water stagnation and a high degree of salinity; for this reason, marshy soils and brackish waters should be avoided.

 

Windy areas - paulownia suffers from strong winds, and therefore areas where the wind exceeds 50 km / h are not recommended ; in the presence of frequent winds above 30 km / h, the use of braces may be recommended until the trunk is sufficiently lignified.

 

Precipitation and water supply - characteristics of paulownia, as already seen, are the developed root system and the size of the leaves; precisely the large leaves, if on the one hand they favor the very rapid growth of the plant through photosynthesis, on the other hand they involve a high level of evapotranspiration (understood as the quantity of water released and which must be restored), obviously higher in the hot seasons. In Italian latitude, the hot season has always been characterized by low rainfall, and therefore, if adequate growth levels are to be achieved, an irrigation supply through irrigation systems is therefore essential.

 

Fertilizers - For a rapid development of the plant, and for obtaining a good quality wood, it will be important to intervene by providing the necessary annual contribution in terms of fertilizers, which can be chemical or organic. For the formulation of an adequate fertilization program, it will be necessary to study the chemical and physical analyzes of the soil. As mentioned, the biochar produced with the twigs of the same plantation could be used for the biological fertilization of plants, drastically reducing the quantity of other fertilizers.

 

Light - light is a fundamental element for the growth of paulownia, a plant that loves the sun and needs the sun to express very rapid growth levels. To this end, it will therefore be important to evaluate the overall hours of light in the plantation area, as well as the appropriate planting layout to prevent plants that are too close to bring shade to each other, considerably slowing down the growth rate of the trees inside. of the plantation.