Plant of the month – May 2016

PONCIRUS trifoliata, trifoliate orange, bitter orange

Companion with Mediterranean charm ...

The rhododendrons and azaleas are not only beautiful but are also now gradually in full bloom and are causing quite a stir in the Bruns Nursery’s Rhododendron Park in Gristede. The numerous woody rarities planted along the edge of the paths also deserve quite the attention by visitors. There is a lot to discover during a tour through the park.

For example, the poncirus trifoliata, offers a touch of the south in the Rhododendron Park Gristede with its Mediterranean charm and fragrant scent.

Poncirus trifoliata is found in the wild in China and in Japan, where it is often used as a hedge plant. The trifoliate orange is one of the most important root stocks for citrus plants in many parts of the world.

The trifoliate orange itself is the cold-hardiest citrus plant which is planted in Europe.

The numerous white flowers appear right near the new shoots. The relatively large, ambisexual flowers usually grow alone, sometimes in pairs in the axila. The delicate flowers look very similar to real orange blossom. Poncirus trifoliata blooms on last year's wood and during warm, windless weather, exudes a very light citrus scent.

The branches are significantly flattened and with strong, up to 7 cm long thorns that make them look like they are growing in a zigzag pattern.

Poncirus trifoliata either grows as matted bushes or wide, small trees, with lots of thorns and often has a bizarre picturesque growth. Birds are quite happy to seek shelter in the thorny poncirus plant, similar as with blackthorn. In autumn the foliage puts on a lovely display of bright orange-yellow in colours.

The pleasant and fragrant yellow fruit can also be used for decoration. When picked in early November and placed in the living room for decoration, they hold about 4 weeks.

Poncirus trifoliata was first described in 1763 by the Swedish naturalist Carl von Linne, and introduced to Europe in 1850. There is also a decorative variety called ‘Flying Dragon' or Poncirus trifoliata var. Monstrosa which grows to a maximum of 2 meters with corkscrew-like growth. The thorns of this variety are bent backwards, and the fruit is slightly smaller than that of the species.