Conifer Trees: Picea abies

PICEA

One of the largest and most important genera of conifers, the “Spruces” have produced a multitude of good garden plants. The species are mostly conical in habit, particularly the larger growing kinds, but amongst the cultivars such is the variety available that almost any shape can be found! All of the species and many of the cultivars of the Spruces produce cones and these are oval or cylindrical in shape which, unlike those of the Abies, are pendulous in habit. The leaves are short and needle-like, the dormant buds often very conspicuous. Most species are varying shades of green, but some include cultivars which are blue, silver or grey adding considerably to the range of colour. They will succeed in most soils, but there are only one or two species that will do well in dry or impoverished conditions and not all will stand exposed positions. Some can be particularly susceptible to spring frosts, Red Spider and other pests.

Picea abies

Large tree.After ten years: 3-4m. Ultimate Height: 30-40m.

The “Common Spruce” or “Norway Spruce” is the most widely grown Picea in cultivation and is familiar to all in Britain as the typical “Christmas Tree”. In its typical form it is not a particularly good garden plant since although it looks attractive when young it frequently becomes somewhat unsightly with age, particularly if it has been dug up and used for several years to carry the Christmas decorations! It becomes a large tree, foliage dark green with brown winter buds and is used mainly for forestry purposes. It occurs in its natural state in forests through Northern and Central Europe. It is sometimes still listed in some nursery catalogues as P. excelsa.

The dwarf forms have usually originated from a “Witches Broom”, occurring on a normal tree, and since the stunted and sometimes malformed growth taken from one of these curious growths will strike readily, from cuttings, the resulting plants have an attractive character of their own. But because of their origin these forms are liable to “revert”— throwing out strong and uncharacteristic growth. This should always be cut away as soon as it is noticed. There are a large number of these dwarf forms in cultivation and since some of them are very similar unfortunately much confusion and uncertainty exists in the nursery trade.

Picea abies ‘Acrocona’

Medium Tree. After ten years: 2-2.5m. Ultimate Height: 6-8m.

Picea abies ‘Acrocona’This cultivar is mainly interesting for its capacity to cone at an early age. This can be seen from the young plant in the picture, which within 5 years has formed many large cones at the tips of the branches. The tree itself makes a large bush, spreading if not trained in early years, with pendulous branches.

It was discovered in Sweden at the turn of the last century and although by no means a rare plant, it will not be found listed in many nursery catalogues.

Picea abies ‘Clanbrassiliana’

Dwarf Tree. After ten years: 20-30cm. Ultimate Height: 2m. x Ultimate Spread: 3m.

Specimens of this cultivar would appear to be somewhat variable, although there are many masquerading under this name which bear no resemblance to the true plant. This makes a very slow growing globular bush, sometimes almost flat-topped when young, but developing into a round topped small tree in old age. It has a very dense branching system with large conical reddish-brown dormant buds which are very conspicuous in winter. The leaves are a dullish mid to light green, and vary noticeably in size on different shoots on the same plant.

Picea abies ‘Gregoryana’

Dwarf Tree. After ten years: 15-20cm. Ultimate Height: 50-60cm. x Ultimate Spread: l-5m.

One of the most popular of the dwarf “Spruces” this is very similar to the much rarer form ‘Echiniformis’ and indeed the two are often confused. They both make dense cushion-shaped plants, wider than high and sometimes irregular in outline in old specimens. The tiny globose buds are a shining yellow-green, but not so conspicuous as ‘Clanbrassiliana’ ; the leaves on both cultivars are a dull grey-green, very narrow, rounded and needle-like.

‘Gregoryana’ differs from ‘Echiniformis’ in being more dense and having fewer, longer and very prickly leaves. For all but the enthusiast it shouldn’t be necessary to obtain both cultivars.

‘Picea abies ‘Nidiformis’

Dwarf Tree. After ten years: 30-40cm. x Spread: 45-60cm. Ultimate Height: l-2m. x Ultimate Spread: 2-3m.

This is a distinct and excellent garden cultivar with a flat-topped, spreading habit. It is very popular on the Continent where it was first introduced and deserves to be more widely known in this country. The plant tends to build up in horizontal layers, becoming quite large in time. The colour is dark green and like most of the garden cultivars of the Norway Spruce it is extremely attractive in early summer, when the foliage tips are a bright fresh green with the new seasons growth.

Picea abies ‘Ohlendorffii’

Dwarf Tree. After ten years: 30-45cm. Ultimate Height: 1.5-2.5m.

Another introduction from the Continent, this cultivar was raised in Germany as long ago as 1845. It makes a broadly conical bush with a very dense habit, the branching system spreading outwards and upwards and the branchlets irregular in growth. The dormant buds are very prominent in winter being dark orange-brown, whilst the leaves are small and a light yellowish-green.

Picea abies ‘Procumbens’

Dwarf Tree. After ten years: 20-30cm. x Spread: 2-3m. Ultimate Height: lm. x Ultimate Spread: 3-4m.

Although classed as a dwarf conifer this is one of the most vigorous of the prostrate Norway Spruces and will eventually cover a large area. The leaves are a medium green colour, the branches layered, the branchlets having ascending tips.

Picea abies’Pumila’

Dwarf Tree. After ten years: 20-30cm. x Spread: 2-3m. Ultimate Height: 1-1.5m. x Ultimate Spread: 3-4m.

This form is somewhat uncommon in cultivation so P. a. ‘Pumila Nigra’ should perhaps be included in this description. Both these cultivars make an irregular flat-topped bush with the lower branches semi-prostrate, the upper ones more erect. ‘Pumila’ makes a low spreading bush of bright green, but the form much more commonly found in the trade is a much darker green and dull in appearance. Both are reliably low growing forms where a less prostrate plant than ‘Procumbens’ is required.

Picea abies ‘Reflexa’

Prostrate or Medium Tree.

It is not possible to state an ultimate height and growth of this cultivar since left to its own devices it will become a sprawling prostrate plant several metres across. Trees of several metres in height are known but such specimens will have been trained up a stem when young. Such a tree with its pendulous main branches and all the growing tips sweeping upwards is most attractive, and the untrained or prostrate form is very effective planted on a large rock garden over which it can “cascade”. It has prominent orange-brown buds, the foliage a dark blue or grey-green. Another pendulous form which makes a narrow column with its branches completely pendulous is P. a. ‘Inversa’.

Picea breweriana

Large tree. After ten years: l.2m. Ultimate Height: 15-20m.

One of the most beautiful of all conifers “Brewer’s Weeping Spruce” is deservedly popular, although not always the easiest species to establish. Of broadly conical habit its branches are clothed with long pendulous branchlets, the leaves a dark blue-green. Like many pendulous forms it is not truly effective until several years old when the plant begins to fill out and take a more mature form. It will do well in both sun and shade but succeeds best in areas of high rainfall, originating as it does from the mountain regions of North West United States.

Picea engelmannii

Medium Tree. After ten years: 2-3m. Ultimate Height: 20-25m.

This little known species is a most attractive garden cultivar with its broad conical habit and dense grey-blue foliage. It has conspicuous brown winter buds and bears reddish-green cones turning light brown on ripening which add further to its garden I worthiness. It grows well in all except the driest areas. The selected form most often offered by nurserymen is P. engelmannii ‘Glauca’.

Picea glauca ‘Albertiana Conica’

Dwarf Tree. After ten years: lm. Ultimate Height: 2-3m.

This is one of the most popular of all conifers, being widely grown as a garden cultivar throughout Europe and North America. It first originated near Alberta in the Rocky Mountains of Canada in 1904, as a chance seedling from Picea glauca albertiana, the “Alberta White Spruce”. If kept to a single leader when young it makes a perfect cone — forming a very slow growing miniature forest tree. Bright green in colour and dense in habit, it becomes particularly attractive in early summer when the new season’s growth appears. Unfortunately it is plagued by certain pests, particularly Red Spider mites and a few doses of a systemic insecticide may be necessary to control these in the summer months. This should certainly not deter anyone from buying this excellent cultivar.

Picea mariana ‘Nana’

Dwarf Tree. After ten years: 7-10cm. Ultimate Height: 30cm. x Ultimate Spread: 50cm.

This very dwarf form of the “Black Spruce” is rather scarce in cultivation but is such an excellent rock garden plant that it should be included in this section of the website. It forms a very tight, congested ball of grey-blue, with the blue predominant in summer. Very hardy and a real gem of a plant.

Picea omorika

Large tree. After ten years: 3-3.50m. Ultimate Height: 20-25m.

The “Serbian Spruce” could be recommended as the best of the larger spruces for garden worthiness. It is both very attractive and adaptable to many soils and situations, hardy and not too rapid a grower. Forming a narrow cone, its branches are short and drooping and upward curving at the tips; the leaves dark green above, glaucous underneath; cones conical and bluish-black. It is very graceful of habit and deserves to be much more widely planted, succeeding well in highly alkaline soils and dry situations and not susceptible to pests as are so many other spruces. It is of course a forest tree in its original habitat in Yugoslavia, but can be effective both as a single specimen or planted in a group.

Picea omorika ‘Pendula’

Medium – Large tree. After ten years: 2-3m. Ultimate Height: L5-20m.

This cultivar has similar foliage to the type, but is much narrower in form and its branches are, as the name suggests, much more drooping. An attractive garden tree which although slow to establish and in need of training in the early stages is nevertheless an extremely useful garden cultivar.

Picea orientalis

Large tree. After ten years: 3-4m. Ultimate Height: 45-50m.

Perhaps, like a few other conifers mentioned in this section, the “Oriental Spruce” is eventually too large a tree for most gardens, but there is a place for it in certain situations. It makes a densely-branched, broadly conical tree, with the branches remaining clothed to the ground. The leaves are deep green, very short and overlapping, giving the branchlets a very neat appearance. The cones are purple when young, turning brown on ripening. It is a very distinct and attractive tree and adaptable to most soils and situations.

Picea orientalis ‘Aurea’

Medium Tree. After ten years: 2-3m. Ultimate Height: 7-10m.

Also known as P. o. ‘Aureospicata’, this is much slower growing than the species. It has creamy-yellow turning to golden tips in spring which are most attractive, as can be seen from the photograph, but these fade later in the summer to assume the same green as the remainder of the plant. Where grown well, and it needs an open position, it is a most effective cultivar.

Picea pungens

Medium-Large tree. After ten years: 2-5-3-5m. Ultimate Height: 30-40m.

The “Colorado Spruce” is somewhat rare in cultivation as generally only the glaucous forms are grown and have become very popular garden plants.

Picea pungens glauca

Medium Tree. After ten years: 2-3m. Ultimate Height: 18-25m.

There are considerable variations in habit, rate of growth and colour among the “Blue Spruces” and from any batch of seedlings one could select glaucous-blue forms that would make excellent garden plants. Many of these seedlings have been selected by nurserymen and propagated by cuttings or grafting, giving rise to numerous named cultivars, some of which are unfortunately almost identical. However such is the popularity of these selected Blue Spruces that they are often in short supply, particularly in England. Most forms have the typical rigid branching system, densely covered with stiff leaves of grey-blue. The winter buds are usually brown and the fresh early summer growth a bright eggshell blue, varying in intensity according to the clone.

P. pungens glauca and its cultivars are quite adaptable, very hardy and succeeding better in drier climates than some species. All the following cultivars come under the “Glauca” group, and in many nursery catalogues “Glauca” precedes or is part of the cultivar name.

Picea pungens ‘Endtz’

Medium Tree. After ten years: 2-2.5m. Ultimate Height: 7-10m.

There have been and will continue to be arguments among gardeners and nurserymen as to which is the bluest of the Blue Spruces and I don’t intend to enter into the arena on this subject! However this cultivar must be equal to any. It has a densely clothed, conical habit and is perhaps better known on the European continent than in England. There is another somewhat similar medium growing cultivar in P. p. ‘Hoopsii’ which is also claimed to be the bluest form in cultivation.

Picea pungens ‘Globosa’

Dwarf Tree. After ten years: 45-60cm. Ultimate Height: 1-1-25m. x Ultimate Spread: 75cm.-lm.

This makes a slow growing dense blue bush, somewhat irregular in shape holding its colour well throughout the year.

Picea pungens ‘Koster’

Medium Tree. After ten years: 2-3m. Ultimate Height: 7-10m.

Perhaps the most popular and readily available, the “Koster Blue Spruce” has also been the longest in cultivation so perhaps has had an unfair advantage over its rivals! As mentioned earlier most of these cultivars will have been grafted and for the larger growing forms it may take at least two or three years of patient training to get the leader to go upright and for the rest of the plant to fill out. Usually it is well worth both the wait and the trouble.

P. p. ‘Koster’ is usually regularly shaped in form and silver-blue, holding its colour well in winter.

Picea pungens ‘Prostrata’

Semi-Prostate. After ten years: 2-3m. Ultimate Height: lm. x Ultimate Spread: 4-5m.

This is a very variable form, the name covering perhaps many cultivars in their prostrate forms. If a graft is made from a lateral branch as opposed to an upward leading one, unless trained upwards it will remain more or less prostrate. Often many prostrate or semi-prostrate forms will have arisen from the cultivars mentioned above and if a prostrate cultivar is required any tendency for a leader to develop should be stopped by a careful pruning of the offending branch. These are really all cultivariants although one may find certain cultivars will produce more stable prostrate forms than others.

Picea pungens ‘Moerheimii’

Medium Tree. After ten years: l-5.2m. Ultimate Height: 7-10m.

This cultivar is another attractive and popular glaucous form, dense in habit and making a tiered effect with its layers of branches.

Picea pungens ‘Montgomery’

Dwarf Tree. After ten years: 45-60cm. Ultimate Height: 1-1.5m. x Ultimate Spread: 75cm.-lm.

An introduction from the United States where it is very popular. It is somewhat similar to P. p. ‘Globosa’.

01. September 2011 by admin
Categories: Conifers, Trees | Tags: , , | Comments Off on Conifer Trees: Picea abies

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