Poncirus trifoliata

Poncirus trifoliata (07/12/2015, Kew Gardens, London)

Position: Full sun, to light shade

Flowering period: Spring

Soil: Moist, well drained

Eventual Height: 7m

Eventual Spread: 6m

Hardiness: 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b

Family: Rutaceae

Poncirus trifoliata Autumn Leaf (07/12/2015, Kew Gardens, London)

Poncirus trifoliata is a deciduous large shrub or small tree with a rounded habit. Its dark green leaves are trifoliate, each leaflet being elliptic with entire margins, the centre leaflet being up to 5cm long and 2.5cm across. Its leaves turn yellow in autumn before they fall. Its branches have sharp thorns which are up to 5cm long. Its slightly fragrant white flowers are waxy and up to 5cm across. Its fruit are spherical, initially green, maturing to orange and up to 4cm across.

Poncirus trifoliata Fruit (07/12/2015, Kew Gardens, London)

Poncirus trifoliata, commonly known as the Chinese Bitter Orange, Japanese Bitter Orange, Hardy Orange or Trifoliate Orange, is native to China and Korea. Poncirus trifoliata is synonymous with Citrus trifoliata.

The etymological root of the binomial name Poncirus is from an old French name for a type of Citrus. Trifoliata is derived from the Latin tres meaning ‘three’ and folium meaning ‘leaf’.

The landscape architect may find Poncirus trifoliata useful as a small tree that produces interesting fruit. It may also be grown as an effective barrier hedge.

Poncirus trifoliata Stem with Thorns (07/12/2015, Kew Gardens, London)

Ecologically, Poncirus trifoliata flowers are attractive to pollinating insects.

Poncirus trifoliata prefers moist, sandy loam soils. It tolerates most pH of soil.

Poncirus trifoliata requires little maintenance. This tree may be cut back severely without harming it.



Landscape Architecture

Phellodendron amurense

Phellodendron amurense (28/09/2014, Kew Gardens, London)

Position: Full sun

Flowering period: Late spring

Soil: Moist, well drained

Eventual Height: 15m

Eventual Spread: 20m

Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b

Family: Rutaceae

Phellodendron amurense is a deciduous tree with a rounded spreading habit . Its mid green leaves are odd pinnate with up to 11 leaflets and are aromatic when crushed. Its leaflets are ovate with entire margins, up to 11cm long and 4cm broad. Its leaves turn yellow before they fall in autumn. Its branches. Its grey/ brown bark is ridged and corky in mature trees. This tree is dioecious and its yellow/ green flowers are up to 2mm across. Its black fruit is a fleshy drupe which is up to 1cm across and persist into the winter months.

Phellodendron amurense Leaf (28/09/2014, Kew Gardens, London)

Phellodendron amurense, commonly known as Amur Cork tree, is native to east Asia, including north China, Manchuria, Korea, Ussuri Amur and Japan. In its native habitat it grows in deciduous woodland. This tree is considered as invasive in many parts of the USA and Canada. This tree will readily reseed given the right conditions.

The etymological root of the binomial name Phellodendron is derived from the Greek phellos meaning ‘cork’ and dendron meaning ‘tree’. Amurense is derived from the Latin and means ‘from the region of the Amur River, east Siberia’.

The landscape architect may find Phellodendron amurense useful as an attractive parkland tree. Once established this tree is drought tolerant.

Phellodendron amurense Bark (28/09/2014, Kew Gardens, London)

Ecologically, Phellodendron amurense fruit are attractive to some birds.

Phellodendron amurense prefers moist, humus rich, well-drained soils. It tolerates most pH of soil.

Phellodendron amurense requires little maintenance.

Citrus × paradisi

Citrus × paradisi (07/09/2014, Walworth, London)

Position: Full sun

Flowering period: Spring

Soil: Moist, well drained, acidic

Eventual Height: 6m

Eventual Spread: 5m

Hardiness: 9a, 9b, 10a, 10b, 11

Family: Rutaceae

Citrus × paradisi Leaf (07/09/2014, Walworth, London)

Citrus × paradisi is a small evergreen tree with a rounded habit. Its dark green shiny  leaves are oblong to elliptic with serrulate margins, up to 15cm long and 5cm broad. Its leaves emerge purple/ green. Its branches have occasional sharp spines. Its fragrant white flowers are waxy with a purple base and up to 5cm across. Its yellow fruit are spherical and up to 15cm across.

Citrus × paradisi, commonly known as the Grapefruit, was first bred in Barbados in the eighteenth century.

Citrus × paradisi Fruit (07/09/2014, Walworth, London)

The etymological root of the binomial name Citrus is is from the ancient Latin name for this tree. Paradisi is named after Count Giovanni Paradisi of Modena (1760-1826).

The landscape architect may find Citrus × paradisi useful as a fragrant small evergreen tree that produces edible fruit. It can only be grown in the warmest parts of the UK.

Citrus × paradisi Bark (07/09/2014, Walworth, London)

Ecologically, Citrus × paradisi flowers are attractive to pollinating insects.

Citrus × paradisi prefers moist, sandy loam soils. It prefers an acidic pH of soil.

Citrus × paradisi requires little maintenance. This tree may be cut back severely without harming it.