Pyrus pyrifolia Kosui - Asian Pear

The Nashi Kosui, in Latin Pyrus pyrifolia 'Kosui' is the most popular apple-pear variety in Japan. Hardy (up to -15°C), this small tree, very similar to the common pear tree, produces medium-sized fruits, called nashis, with a subglobose shape, rounded like an apple. Its skin is slightly rough, quite thin, golden bronze, taking on bronze-brownish hues when ripen and marked all over its surface with white dots. Its refreshing white flesh is fine, crisp, sweet and very juicy, with a taste of pear, sometimes granular in its centre. The harvest takes place from mid-August to mid-September, the fruits are consumed as soon as they are picked, according to their ripeness, and can be stored for a few weeks in a cool place. The Nashi is surprising and pleasant in the mouth when eaten raw. Cooked, it is a variety that lends itself well to many recipes for jams, compotes, pastries, and desserts. This Japanese pear tree prefers a sunny exposure, in well-draining, moist, deep, rich, and non-calcareous soil.

The Nashi, Pyrus pyrifolia or serotina, more commonly known as apple-pear, Japanese pear, Asian pear, or sand pear, is a fruit tree belonging to the Rosaceae family, like the Pear tree or the Apple tree. It is native to China and Japan, where it grows up to medium altitudes. Cultivated for a long time in Asia, it has recently appeared elsewhere. "Nashi" is a Japanese word that can be translated as "pear" which refers to both the shrub and the fruit. Although the Nashi is not a cross between an apple tree and a pear tree, its fruits are sometimes called "apple-pear" because they resemble apples while having the texture of pears.

The Kosui variety is a hybrid that was developed at the National Fruit Tree Research Station in Japan in 1959. It is a very productive variety, with rapid, abundant and regular fruiting. It forms a small tree with a fairly upright structure that can reach 3 to 4 metres in height, producing many slightly arched branches, with a spreading habit. Its habit is well suited to tall forms (on a stem), low forms (in a goblet shape), or espalier forms (fan-trained). Its deciduous foliage is composed of large lanceolate, 7 to 10 cm long, alternate, dark green and shiny leaves, taking on orange-red autumnal hues before falling. Flowering occurs in April, which generally protects it from frost. The white, single, 2 to 3 cm diameter, nectar-rich flowers are grouped in umbels. They can be destroyed by frost from -2 to -3°C. It is a fairly hardy tree that can withstand temperatures around -15°C, and is suitable for cultivation in all regions, including low altitudes. This Japanese Pear tree is said to be self-sterile or self-incompatible, the flowers cannot fertilise themselves. That is why the presence of other pear tree varieties, nearby, whose flowering occurs at the same time, is necessary for cross-pollination, and thus increase the number of fruits. The varieties Nashi Hosui, Nashi Shinseiki, or William's are good pollinators for Nashi 'Kosui'. Kosui itself is a good pollinator for other pear trees.

The harvest begins around mid-August, and continues until September. The fruits are consumed as soon as they are picked, according to their ripeness. The nashi is ripe when the skin is smooth and taut, and the fruit is soft around the peduncle. The nashi can be eaten raw or cooked. It is pleasant to bite into with the skin, which sets it apart from other fruits. It is appreciated in jams, compotes, pastries (pies, crumbles...), and desserts where it pairs well with chocolate, rhubarb, or panna cotta, not to mention fruit salads. It is important to pick the fruits only when they are ripe, as they do not ripen further after harvest.

The nashi is rich in water and refreshes and quenches thirst. It is very fleshy, so provides a great feeling of satiety. It is low in calories, rich in potassium and magnesium, with a significant copper content. Its content of vitamins C and K, antioxidants, and fibres makes the Japanese pear a healthy choice. It is invigorating, energising, and rehydrating. The fruits can be stored from a few weeks to 3 months after harvest in a cool, clean place, protected from light at a temperature around 8 to 10°C, or in a cold room, sealed off from outside air at a temperature of 1 to 3°C.

In the Nashi category, Nashi Kosui is a disease-resistant variety that is easy to grow. To obtain fruits of good quality, thin to reduce the number of fruits on the tree. Pruning for air circulation, by removing some branches in the centre of the tree, will provide light and give the fruits a beautiful colouration. This will also limit the occurrence of diseases. Appreciated for its fruit qualities, the Nashi is also decorative due to the elegance of its shape and surprising due to the autumnal colouration of its foliage, making it a real asset in the garden. With a wide range of varieties, it is easy to find the one that best suits your requirements.