This group, commonly known as the false cypresses, consists of a number of species and innumerable varieties of plants and includes some of the most popular garden conifers in the United Kingdom. They are great fordisplays as there are many dwarf varieties, and also make breat Bonsai projects. Even the garden giants can be tamed for indoor use if cultivated carefully.
However, none of the species is native to the United Kingdom or to Europe, as one might expect, but they mostly originate from North America and Japan.
Many are still referred to as Cupressus but this is in fact a separate group.
Most are, preferring situations of good but a reasonable amount of moisture.
Chamaecyparis lawsoniana, the Lawson cypress, is perhaps the best-known conifer type planted in Britain, but was itself only introduced from western North America barely a hundred years ago. A great many varieties of this species have since been introduced and are often lumped under the general heading of Lawson’s but such is the variety of colours, shapes and sizes in this group that this can be misleading. C. lawsoniana itself is often used as a hedging plant these days but seldom as a specimen, having been superseded by some of its varieties for such purposes. Although varying somewhat in habit and rate of growth, mostwould grow 10 to 12 ft. in ten years and eventually anything from 75 to 100 ft. at maturity.
C. l. Allumii is one of the most widely grown varieties with bluish foliage and a narrow pyramidal habit. Of medium growth, it could be expected to grow 8 to 10 ft. in its first ten years and eventually 30 to 40 ft. In my opinion C. l. columnaris sometimes listed as columrzaris glauca is a more attractive variety, varying in its denser foliage and as the name suggests a more columnar habit. The blue is if anything more intense. Its rate of growth is a little slower than allumii and it would be likely to reach only 30 ft. at maturity.
There is little doubt that C. l. ellwoodii is the most popular garden conifer in Great Britain. It has close grey-green foliage and although often classed as a dwarf or rock garden conifer it grows quite vigorously in the first ten years to 6 ft. or so and eventually reaches 20 ft. or more. However, it is an attractive and valuable variety, the habit of which can vary but would normally be described as columnar.
Of fairly recent introduction is Ellwood’s Gold, a copy in habit of ellwoodii if a bit slower in growth. Less a real gold than the name suggests, it is nonetheless a good garden plant and particularly pleasant in spring when the new yellow-tipped growths appear. C. 1. lanei is one of the popular medium-growing, golden-yellow varieties and still one of the best. Because there is so little else to see in the winter I feel it is important when choosing conifers to make a selection with this in mind. Lanei suits this purpose admirably, being nearly as bright a yellow in winter as in summer The variety lutea is equally useful but lacks the bright winter colour. Both reach about 8 to 10 ft. after ten years and ultimately 30 to 40 ft.
C.l. minima aurea is, as one might suspect, a dwarf form but to my mind one of the most beautiful of all conifers. It has densely packed, bright yellow foliage the year round, ideal for a rock garden or at the front of a heather border. Growing about 1 ft. in ten years and even after twenty or thirty years still likely to be under 6 ft., it could not be described as a plant that gets out of hand! Plants on sale are likely to be small as one might expect.
There is a green and more rounded variety in minima glauca which has a similar rate of growth to minima aurea and tends to grow on you with age! Pembury Blue has probably the bluest colour of all the medium-growing varieties especially in summer when its foliage attains a brilliant silvery hue. Broadly conical in habit, itsare coarser and more open than either allumii or columnaris. At ten years of age it can be expected to be about loft, and eventually 30 to 40 ft. tall.
C. l. pygmaea argentea is another gem of a plant. A really slow-growing conifer which will even in maturity not exceed 3 ft., reaching perhaps 1 ft. after ten years. Compact and rounded in habit the bottom foliage is sea green but all the exposed growing tips are silvery white the year round. If planted in a sunnyagainst a contrasting background, a quite startling effect can be created.
C.l. stewartii is one of the oldest of the golden varieties but is still distinct and remains a useful plant for a medium to large garden. It is in fact more golden than yellow, but tends to lose its colour more in winter than either lanei or lutea. At ten years it will grow to about 10 to 12 ft. and ultimately 30 to 40 ft.
Although there are a great many other golden varieties grown, many are not as proven as the three so far mentioned, although Stardust, a recent introduction from Holland, looks distinctand seems to be an easy grower with good, year-round colour.
It is inevitable that many good varieties cannot be mentioned because of space, but a last and distinctive C. lawsoniana form is of a completely different habit. C. l. tamariscifolia is a spreading variety eventually forming a large bush much wider than high. It has bright green foliage winter and summer and this comes in overlapping sprays. It is sometimes listed in catalogues under the name of knowfieldensis. In ten years it will have attained a height of 3 ft. and a spread of 5 ft., and at maturity possibly 8 to loft, high by 12 to 15 ft. across, so it will eventually need considerable space.
C. nootkatensis originates from western America and is generally much hardier than C. lawsoniana, but certainly not so well known. It is perhaps better known as one of the parents to the hybrid Cupressocyparis leylandii, although a useful tree in its own right. Reaching 10 to 15 ft. in its first ten years, it will eventually attain forest-tree proportions of 90 to 100 ft. There are one or two useful forms —glauca, similar in habit but a more glaucous tinge to the foliage, and an attractive form lutea which deserves wider recognition. There is also a weeping form pendula which becomes an extremely beautiful plant with age but admittedly does not make much of a show in its first five to ten years. All are medium to large growers and not really suitable except for the larger garden.
C. obtusa originates from Japan and although the species known as the Hinoki cypress is a large-growing tree, it has given us a great many attractive garden forms, only a few of which can be mentioned. Perhaps the most widely known variety is nano gracilis which has the typical dark glossy green foliage of the species. It has large, shell-shaped, flattened sprays and although eventually assuming a broadly conical shape it spends some years as a rounded bush. It is often seen as the typical Japanese garden orplant. Although at ten years reaching about 2 ft., it can at maturity attain 15 to 18 ft., but one could be safe for a number of years planting it on a rock garden.
There are several extremely dwarf forms which even after fifty years may not be more than 2 ft. in height. The true C. o. nana is one of these, forming a flat-topped miniature bush. One of my favourite conifers is C. o. nana lutea which is again of a very slow growth — at ten years it will be about 1 ft. high but will be unlikely to ever exceed 3 ft. It has wonderful golden foliage the year round with a touch of white in the outer. A choice plant but ideal for a small garden and once again it needs planting in the sun.
C. pisifera is another species originating from Japan and is known as the Sawara cypress. The species is not a good garden plant although there are many varieties of great merit. However, all varieties share the likes of the species in that they like ample moisture at theand not too arid an atmosphere or cold winds. They do not normally grow so well in highly alkaline or heavy clay soils as in acid or peaty conditions.
C. pisifera Boulevard was introduced some years ago in the United States but seems far more suited to the English climate and has achieved quite rapid popularity for a relatively recent introduction. Although attractive the year round it is at its best in summer when the foliage turns an intense silvery blue. Its habit is conical, the foliage dense and although classed as a dwarf conifer it will after ten years reach 6 ft. and ultimately perhaps 15 to 20 ft.
A most unusual but nonetheless attractive variety of the Sawara cypress is filifera aurea. Of a bright golden-yellow colour both winter and summer filifera aurea and its green forms have unusual thread-like foliage. As young plants they can look scruffy but give them a year or two and they will build up into extremely graceful bushes of a broad conical outline. Filifera aurea at ten years old will be about 3 to 4 ft. and eventually will reach 15 to 18 ft.
For a real dwarf C. p. nana takes some beating. It has tightly congested foliage of mid-green although there are forms which are more than open in habit. The true plant will remain less than 6 in. high in its first ten years and probably never exceed 18 to 24 in. at maturity, but many have a spread of 3 ft. or more by that time. Any signs of a stray shoot trying to grow away should be pruned out immediately.
Lastly to varieties which are popular and useful garden plants but which sometimes get confused with each other — and one can hardly wonder at it when the names are so similar. C. p. plumosa aurea and C. p. plumosa aurea nana both have soft feathery foliage but plumosa aurea grows 4 to 5 ft. in ten years and ultimately over 20 ft. whilst plumosa aurea nana as the name suggests would reach about 2 ft. and ultimately only about 6 ft. The latter is also much more golden in winter and in my opinion a much more desirable plant.