Conifer Trees: Pinus
The “Pines” form a large genus containing a great many species and cultivars some of which are of excellent garden value. Most of the larger growing species are conical or rounded in shape when young, becoming irregular and flat-topped with age. They add further dimensions of form and colour to the Conifer family, having needle-like foliage in bundles of two to five and quite unlike the leaves of most other genera. Cones vary in shape from narrowly conical to broad and rounded and many species retain these on the tree for several years although the seed usually ripens in their second year. On many species and cultivars the late spring or early summer growths are extremely attractive and often unusual. Also in late summer on many species the previous year’s leaves drop leaving the inside of the plant unfurnished and so as they age many Pines assume a gnarled and rugged appearance, adding character to the landscape and garden.
Among the Pines there are species suitable for most situations, many being quite content in poor drywhere no other trees will grow, but one thing they have in common is a dislike for shady conditions and a polluted atmosphere.
Some species such as P. sylvestris and P. nigra are grown commercially for timber, but there are many slower growing species and cultivars suitable for theand even the .
Dwarf – Medium Tree. After ten years: 1.5-2m. Ultimate Height: 3-5m.
The “Bristlecone Pine” is reputed to be the oldest living thing and although not grown widely in England or Western Europe it is quite popular in the United States. It originates in the South Western part of that country and old specimens have been found in some regions which are over 5,000 years old.
In cultivation it is often no more than a shrub with glaucous green leaves closely adpressed to the branchlets. It has the appearance of being covered in white resinous spots, which though unique may not be considered by some to be particularly attractive.
Large tree. After ten years: 3-4m. Ultimate Height: 20-30m.
The “Mexican White Pine” is a most graceful pine somewhat similar to P. griffithii. It is considered less hardy than that species, succeeding best in milder regions. The leaves are in fives, long and greyish-green. Long cones are borne on quite young trees.
Dwarf – Medium Tree. After ten years: 1-2m. Ultimate Height: 10-15m.
The “Arolla Pine” or “Swiss Stone Pine” is one of the best medium sized garden Pines. Dense in habit it has the added advantage of remaining clothed to the ground with foliage even as a mature specimen. The young spring shoots are a distinctive orange-brown and it is by these that P. cembra can usually be identified from other five leaved species. The leaves outside are dark blue-green with a contrasting whitish-blue colour on the inside. The cones are erect, ovoid and dark blue. In my opinion this species should be better known and more widely planted than it appears to be at present.
Medium Tree. After ten years: 2-3m. Ultimate Height: 5-6m.
The “Beach Pine” or “Shore Pine” makes a medium sized tree or often a large bush. It is not used much in the British Isles as a garden conifer, although as the common names suggest it can be a very useful tree for coastal areas, succeeding well on light sandy soils. It dislikes lime so should not be planted in chalky soils.
P. contorta is a two leaved species, the leaves being twisted and a yellowish-green, with the cones yellow-brown and usually borne in pairs or clusters.
Medium – Large tree. After ten years: 3-4m. Ultimate Height: 25-30m.
The “Japanese Red Pine” is similar to the “Scots Pine”, P. sylvestris in habit as well as in the reddish colour of its bark. The leaves are in pairs and bluish-green. Although conical when young like the Scots Pine, this species becomes irregularly flat-topped with age.
Pinus densiflora ‘Umbraculifera’
Dwarf Tree. After ten years: 75cm.-1m. Ultimate Height: 3m. x Ultimate Spread: 3m.
The cultivar name ‘Umbraculifera’ is the latin word for Umbrella and this gives quite a reasonable description of the habit of this plant. It is slow growing, with densely arranged dark green leaves. It is a very attractive conifer and an ideal garden plant.
Large tree. After ten years: 3-5m. Ultimate Height: 30-50m.
This is one of the most beautiful of all the Pines, eventually making a large broad-headed tree and holding its lower branches in an open position. It originated in the lower Himalayas and is commonly known as the “Himalayan Pine” or “Bhutan Pine”. Another five leaved species, the leaves being long and light bluish-green in colour. The cones are long, narrow and pendulous. Not every garden will have space for such a large growing tree, but certainly this species deserves to be more widely planted. Although tolerant of some lime it cannot be recommended for thin chalky soils. P. griffithii is likely to be listed in some catalogues as P. excelsa or P. wallichiana. According to some authorities the latter name is now considered to be the correct one but as P. griffithii is by far the most commonly used it seems sensible to avoid further confusion.
Pinus heldreichii ‘Compact Gem’
Dwarf Tree. After ten years: 25-30cm. Ultimate Height: 1.5-2m. x Ultimate Spread: 1.5-2m.
This cultivar name has been given to a very attractive selected form of the “Bosnian Pine” P. heldreichii lencodermis. It is a dark almost black-green colour and dense in habit. Although it is not likely to be an easy plant to find in nurserymen’s catalogues it will be well worth searching for. The “Bosnian Pine” itself is somewhat variable in habit, of slow to medium growth and making a very useful garden conifer. Like many other good plants it is not known nor planted widely enough.
The “Mountain Pine” is so variable in rate of growth and habit that it is necessary to forego the use of symbols. Generally as seen in cultivation P. mugo is a medium to large shrub of dense bushy habit. It also goes under the name P. mugo mughus or P. montana. Being so variable from seed, selection has to be made to obtain the most desirable forms. This is how the named cultivars of this species have arisen, but they have after selection been propagated by.
The young shoots are light green, the leaves are in pairs and dark green. P. mugo is a useful garden plant and adaptable to most soil conditions and being tolerant of lime. Only the dwarfer named cultivars can be recommended for theas the species is likely to become too large.
Pinus mugo ‘Gnom’
Dwarf Tree. After ten years: 60-75cm. x Spread: 60-75cm. Ultimate Height: 1.5-2m. x Ultimate Spread: 1.5-2m.
This is one of the most widely grown dwarf cultivars of the “Mountain Pine”. It is dark green and of compact habit and very suitable for the rock garden.
Pinus mugo var. pumilio
Dwarf Tree. Prostate.
This is a botanical variety widely distributed in the Central European Alps. It is often seen as a prostrate shrub, spreading as much as 3m. And sometimes as high as 1.5-2m. It has an erect branching habit and very prominent winter buds, making it a most attractive garden plant.
Large tree. After ten years: 3-4m. Ultimate Height: 20-40m.
The “Austrian Pine” becomes a large tree althoughdo differ quite considerably, giving rise to some denser, slower growing forms. It makes a most useful garden plant for the larger garden and is excellent for windbreaks. P. nigra withstands extreme conditions better than most Pines, succeeding well both on lime soils and in coastal areas. An all purpose plant indeed! It is an attractive species, usually of dense habit and dark green in colour. It is two leaved with young shoots a yellowish-brown, these making an effective contrast in spring. Conical when young it loses its bottom branches with age then becoming umbrella shaped. P. nigra is also referred to as P. nigra austriaca and as might be imagined originates from Austria and the surrounding legions of Italy, Greece and Yugoslavia.
Pinus nigra ‘Hornibrookiana’
Dwarf Tree. After ten years: 50-60cm. x Spread: 60-75cm. Ultimate Height: 1.5-2m. x Ultimate Spread: 1.5-2m.
This form is worth mentioning as an attractive conifer for the small garden or rock garden. It is dark lustrous green, with a compact ascending branching habit. It was discovered as a “Witches Broom” on an Austrian Pine in Rochester, New York, U.S.A.
Pinus nigra var. maritima
Large tree. After ten years: 4-5m. Ultimate Height: 30-40m.
Often referred to as P. laricio, the “Corsican Pine” differs from the “Austrian Pine” in having a single, straighter stem with branches tending to be more horizontal. It is also of a more open habit with grey-green instead of dark green leaves. An adaptable plant the Corsican Pine is a useful timber tree and is grown widely for that purpose.
Pinus nigra ‘Pygmaea’
Dwarf Tree. After ten years: 50-60cm. Ultimate Height: 2-3m.
This cultivar was collected in the wild in the highest regions of Mt. Ansaro in Italy. It is very slow growing making a rounded bush, the leaves twisted and densely but evenly arranged. Normally a dark, dullish green it turns an unusual and attractive yellow in the winter months.
Medium Tree. After ten years: 2-3m. Ultimate Height: 7-10m.
Although in the wild the “Japanese White Pine” will make a medium to large tree it will very seldom reach its normal height in cultivation. A five-leaved species, with light bluish-green leaves which have silvery inner surfaces. The cones come in clusters or sometimes singly and are greenish-blue until ripe. Some Pines drop their previous years leaves annually but P. parviflora retains its leaves for four years so it is always seen densely clothed adding to its attraction as a garden plant. In my opinion this should much more widely planted than at present.
Pinus parviflora ‘Glauca’
Medium Tree. After ten years: 2-3m. Ultimate Height: 7-10m.
A selected clone of the species, this cultivar is a much better colour with a more ascending habit. When young it is rather sparsely branched and these tend to be somewhat irregularly placed. It is an excellent garden plant holding its bluish colour well through- out the winter.
Large tree. After ten years: 4-5m. Ultimate Height: 50-60m.
The “Ponderosa Pine” or the “Western Yellow Pine” is native to the Rocky Mountain areas of North America and although somewhat variable it usually becomes a large tree. It is narrowly conical in habit, the stout trunk having a reddish-brown scaly bark. The branching system is open, spreading or drooping whilst the leaves, produced in threes, are extremely long dark green and densely crowded on the branchlets. It is a most distinctive tree, but can only be recommended for the larger garden.
Medium Tree. After ten years: 3-4m. Ultimate Height: 10-20m.
Known as the “Umbrella Pine” or the “Italian Stone Pine” this is native to the Mediterranean regions and is not used greatly in more northern countries, being less reliably hardy. Its leaves are in pairs, long and light green, the habit rounded when young, becoming flat-topped or umbrella shaped with age. It does well in costal areas and is a common feature of Italian scenery.
It is extremely difficult to categorise this species through the use of symbols as it is somewhat variable in habit. Known as the “Dwarf Siberian Pine” in England and the “Japanese Stone Pine” in the United States, P. pumila usually forms a medium sized or prostrate shrub. It is closely related to P. cembra and some of the dwarf forms of that species are often difficult to distinguish from P. pumila. Of dense, usually mound-like form, the Dwarf Siberian Pine is light green with bluish inner surfaces to the leaves. There are one or two cultivars of this species which have been selected for their blue colour of which P. p. ‘Dwarf Blue’ is a most attractive form. The species itself is a most valuable garden plant, being extremely effective in the heather garden.
Large tree. After ten years: 5-7m. Ultimate Height: 30-50m.
The “Weymouth Pine” or “Eastern White Pine” is widely distributed throughout the Eastern part of North America. It makes very rapid growth and although looking not quite hardy it obviously is! Of pyramidal habit when young this becomes umbrellalike with age. Five leaved, the colour is bluish-green. An attractive tree in the young stages, P. strobus really becomes too large for most gardens, but it has given us a few useful dwarf forms.
Pinus strobus ‘Nana’
Dwarf Tree. After ten years: 50-75cm. x lm. Ultimate Height: 2-2.5m. x Ultimate Spread: 3m.
This name would appear to cover several very similar forms that have turned up in the seed beds. Plants offered under this name will be slow-growing, usually wider than high with densely set silver bluish-green leaves. As can be seen from the photograph it makes a most attractive plant.
Large tree. After ten years: 4-5m. Ultimate Height: 15-30m.
The “Scots Pine” is probably the most familiar of all the Pines to the British and with good reason—it is the only Pine native to the British Isles! It is somewhat variable in its rate of growth and habit as are so many of the Pinus species although usually the Scots Pine makes a medium sized tree, conical when young, becoming irregular and flat-topped with age. It has reddish bark, a notable characteristic, grey or blue-green leaves which are held in pairs. A common sight in the British landscape P. sylvestris is now planted even more widely for forestry purposes. It is quite adaptable to most soil and climatic conditions, but will not be so successful in wet acid or dry chalky soils. It has produced some useful garden cultivars, most of the dwarfer forms having been discovered as “Witches Brooms”.
Pinus sylvestris ‘Aurea’
Medium Tree. After ten years: 1-1.5m. Ultimate Height: 5-6m.
This cultivar is much slower growing than the species and although a somewhat nondescript green in summer it turns a clear golden-yellow in winter and is then quite outstanding if carefully situated. It is particularly effective in the heather garden or against a dark background.
Pinus sylvestris ‘Beuvronensis’
Dwarf Tree. After ten years: 60-75cm. x Spread: lm. Ultimate Height: 1-2m. x Ultimate Spread: 2-3m.
This is the most popular dwarf Pine grown in the British Isles being often used as a rock garden plant. It is compact and densely branched in its best form, although as the photograph adjoining shows it may tend to become more vigorous and open with age. Several forms very similar to P. s. ‘Beuvronensis’ are in cultivation which can give rise to some confusion, but fortunately they can all be considered garden worthy plants.
Pinus sylvestris ‘Watereri’
Dwarf Tree.-Medium Tree. After ten years: 1-2m. Ultimate Height: 5-7m.
A strong growing bush, conical when young becoming rounded with age, this cultivar is sometimes offered quite wrongly as P. s. ‘Pumila’. It becomes quite large in time and is an attractive garden plant with its ascending branches and blue-green leaves. The original tree is still in existence in Surrey having been discovered in about 1865. It is now still thriving and has reached approximately 7-5m. in height.