This is a genus of two species of deciduous trees from China and Japan. Botanists have had a long running debate as to whether Cercidiphyllum should be regarded as Magnoliaceae or if they are related to Liriodendron or Euptelia. This is because of the nature of their flowers which are tiny and red, emerging before or with the young leaves. Male and female flowers appear on separate trees. Female flowers have no petals and the debate is as to whether, in a much congested form, these are the same floral structure as in Magnolia or Liriodendron or whether the female flowers are a congested inflorescence made up of many individual flowers and bracts. If the latter interpretation is correct then Cercidiphyllum are a very primitive type of flowering plant.
C. japonicum (Katsura tree) and C. magnificum are grown primarily for their autumn colours. C. magnificum turns a splendid yellow while C. japonicum assumes a pale yellow or smoky pink autumn hue. At the same time a very pungent sweet scent is produced which is similar to burnt sugar.
Both species make exceptional specimen trees although C. magnificum is much the smaller growing of the two. The leaves of C. japonicum are similar to those of a Judas tree (Cercis siliquastrum) and are alternate and ovate to rounded. C. magnificum has smaller oval or kidney shaped leaves. Both species have bronzy new growth and C. japonicum has attractive furrowed bark while C. magnificum has smooth bark and usually only a single leader. C. japonicum is a more branched and spreading tree which can grow up to 70ft and needs plenty of room. There is a superb specimen growing at Tregothnan gardens near Truro where it pairs nicely with a Tetracentron sinense; a tree with similarly splendid autumn colour.
If you do have male and female trees in reasonably close proximity you will find seeds which should be sown immediately when ripe. Cuttings are difficult but can be attempted from semi ripe new wood in midsummer. The only difficulty you may encounter with these trees is scorching of the early new leaves in a latish frost.
Today we offer a number of C. japonicum varieties with very different leaf forms and habits. C. japonicum ‘Red Fox’ (‘Rotfuchs’) has dark purple foliage which appears almost black from a distance. This is a slow growing small tree with a very upright habit. C. japonicum ‘Strawberry’ has leaves with a strawberry tint right through the year. C. japonicum ‘Pendulum’ has featured a few times on our Chelsea stand. It has long weeping and drooping branches and larger leaves than other varieties.
