Poncirus trifoliata

The Poncirus trifoliata, also known as the spiny lemon tree, is a hardy bush with white and fragrant flowers, belonging to the citrus trees family.

It is one of the very few truly hardy citrus trees: it can withstand -15°C (5°F).

An Erect bush, with dense branching, the Poncirus trifoliata measures 3 to 4m (9-13ft) in height as well as in width. Its deciduous leaves are made up of three ovate leaflets, of a tender green colour.

In late spring, the spiny lemon tree produces highly fragrant white flowers, with almost translucent petals. Like its cousins, the flowering is followed by beautiful fruiting. The fruits, larger than a kumquat but smaller than a clementine, are silky and green, becoming yellow in autumn. Not edible raw (they are bitter), they can be consumed once cooked.

The numerous branches bear very large green and sharp thorns. Both ornamental and defensive, the Poncirus trifoliata is often used as a defensive hedge to deter animals.
 

Hardy and easy to grow, it thrives in sunlight, in any type of moist, well-drained and non-chalky soil. It dislikes heavy and waterlogged soils in winter.

The Poncirus trifoliata has a very slow growth and may only flower after the second or third year.