Conifer Trees: Cryptomeria
Cryptomeria japonica is the only species in this genus, but it has given rise to a great many cultivars of garden value. C. japonica is native to Japan and China, and there becomes a large forest tree upwards of 40-50m. It has a broadly conical shape with bright green leaves closely adpressed to the branchlets. In winter the colour changes to bronze-green and this is also particularly pronounced with some of its cultivars. C. japonica is not much grown in Western Europe as a garden plant, becoming far too large for all but the most spacious situations. Both the species and its cultivars seem to thrive better in moist rather than dry soils.
Cryptomeria japonica ‘Elegans’
Medium Tree. After ten years: 1.50-2m. Ultimate Height: 6-8m.
This is a juvenile foliaged cultivar making a large bush or small tree. Browny-green in summer, the foliage turns a very attractive copper-bronze in autumn and winter. Although it will grow reasonably well in some shade it will keep a more compact habit if grown in a more open position and will not be so likely to be damaged by snow. It may be necessary to tie the tree after some years to prevent this happening.
Cryptomeria japonica ‘Globosa Nana’
Dwarf Tree. After ten years: 30-50cm. Ultimate Height: 2m.
Although slow to attain a definite form this dwarf cultivar has the typical foliage of the species but forms a neat rounded bush, wider than high. The branchlets are closely crowded and irregular, seeming to fall on top of each other. The colour is yellowish-green in summer, bluish in winter, and is not to be confused with the cultivar ‘Globosa’ which turns an unattractive rust-red in winter.
Cryptomeria japonica ‘Lobbii Nana’
Dwarf Tree. After ten years: 50-60cm. Ultimate Height: 2-2.5m.
An attractive and graceful looking plant, this cultivar makes a rounded bush, the foliage growth comes in bunches with new leaves shooting out like tentacles from the congested tips of the branches. Light green in summer it becomes a bronze-green in winter. This cultivar is sometimes wrongly seen under the label C.j. ‘Elegans Compacta.’
Cryptomeria japonica Spiralis’
Dwarf Tree. After ten years: 40-60cm. Ultimate Height: 1.5-2m.
This cultivar is distinctive in that the leaves twist round the stem of the branchlets, hence its name, but also for the fact that it stays quite a bright green the year round. It is very slow growing, forming one or two leading shoots, but otherwise becoming a somewhat irregular bush. There appears to be two distinct clones of this cultivar, one of tree-like proportions, but mostly those offered by nurserymen will be the one described here.
Cryptomeria japonica ‘Vilmoriniana’
Dwarf Tree.After ten years: 25-30cm. Ultimate Height: lm.
A popular dwarf conifer, this makes a tight congested bush, particularly in open situations. It turns a rich red-purple in winter but the centre of the plant, because it is tightly packed, can get burnt when snow lingers and freezes. There is another cultivar very close to ‘Vilmoriniana’ called ‘Compressa’ which is even tighter in growth and more purple in winter. As is inevitable one sees these plants often grown and sold under the wrong label, but whichever plant one obtains it will be worth having.