The Content Of The Article:
- Appearance and growth
- Location and ground
- care Tips
- To cut
- Important species and varieties
- Diseases and pests
Spruce is one of the most species-rich species among the conifers. There are a total of around 50 different species that are distributed around the globe in the temperate to subpolar zone of the northern hemisphere. Spruce trees have adapted to the polar climate like almost no other tree species and naturally occur in the temperate zone almost exclusively in the cold mountainous regions. North of the Arctic Circle, they often form pure stands and are thus the most important trees of the so-called boreal coniferous forest. Most spruce species, however, come from the high mountains of West and Central China.
In Germany, the red spruce (Picea abies), often referred to as Rottanne, the only native species. With up to 50 meters in height, it is also the largest native tree species. The red spruce has its natural range in the Alps and in the higher elevations of some low mountain ranges. An old rule of thumb says that it needs at least 600 meters of altitude difference and at least 600 millimeters of rain per year. However, as the most important forest tree in Germany, the red spruce was already extensively reforested in the 19th century - mostly ignoring its natural habitat requirements - and is still the most common forest tree in many low mountain ranges. Only recently there has been a turnaround in forestry, since then mixed forests with a high proportion of beech trees, wild cherries, sycamore trees and other deciduous shrubs are planted at many former spruce locations.
Blue spruce (Picea pungens 'Glauca') and most other spruce species are extremely frost hardy
As garden plants, the Serbian spruce (Picea omorika) and the blue spruce (Picea pungens 'Glauca') were very popular in the 70s and 80s - they were often planted as small groves on larger land. Like all higher spruce trees, they are quite vulnerable to windthrow, which in the past has already led to some building and vehicle damage during storms.
Today, most of the gardens are planted with finely spruce trees with special growth habitats. Especially the dwarf forms of different spruce species are very popular.
Appearance and growth
The wild species of the spruce are all quite high and form slender cone-shaped crowns, which taper evenly upwards and only in very old trees in the open space above go broader. The individual species are sometimes very similar and are therefore not so easy to distinguish. However, they can be reliably distinguished from other conifers, in particular from the very similar firs at first sight, on the basis of a few typical features. The conifers of the spruce trees always grow downwards, while the firs grow upright on the branches. In addition, mature spruce cones fall off as a whole. Pine cones, however, disintegrate into individual scales, while the central spindle first adheres to the branch and is dropped later. The evergreen pine needles are square in cross-section, relatively thick and hard with more or less sharply stabbing point. Fir needles are usually very thin, soft and do not sting. The male flowers of the mostly dioecious spruce are predominantly yellow, the first upright female flowers dyed red.
Location and ground
Most spruce trees prefer sunny to partially shaded locations and are extremely soil tolerant. They usually grow on their natural habitats on rather wet to boggy soils with very different pH values. In the long term, spruce can tolerate no drier soil or clay soils that are too heavy - under these conditions, the risk of windblowing and also the risk of bark beetle infestation are very high. The highest drought tolerance shows the Serbian spruce and the spruce.
For higher species, choose a location that is as wind-protected as possible. In addition, you should always place the trees in the garden so that they do not damage buildings or other structural elements in the event of a wind. On sufficiently permeable, not too dry soils no special preparation of the earth is necessary. You can plant all spruce, which are offered in the container, almost year-round, provided that you ensure a good water supply after planting. As spruces are usually frost hardy, even planting in winter is possible. Larger trees should be secured after planting with a sufficiently long, obliquely set pile, so that they do not tip over in stronger winds. A mulch layer of bark compost prevents the soil from drying out too quickly in summer.
Spruce need no special care.In dry summers, however, you should not wait too long with watering, because especially newly planted spruce trees quickly suffer from a lack of water and are then prone to diseases and pests. Note that decaying spruce needles can acidify the soil due to their high humic acid content. It is therefore urgently recommended to test the soil in the root area regularly for its pH value and to counteract this with a value of less than 5 (with loamy soils under 6) with lime.
Spruce trees do not need a regular cut. If you want to stack the trunks, the late winter is a good time. In addition, young trees sometimes form two peaks - in such cases, you should cut one out of the neck as early as possible. Avoid rash cuts in the old wood, because spruce, like almost all coniferous trees only in the area of the needled shoots new buds formable. You should also not cut off the mainspring, because this completely disfigures the elegant crown of the trees. Although new peaks are formed by mostly side shoots continue to grow upright, but at this point remains an unattractive bend throughout life.
The most suitable species for individual standings are the larger, upright growing species with expressive crowns, such as the mane spruce (Picea breweriana), the oriental spruce (Picea orientalis) and the Serbian spruce (Picea omorika). Even larger expressive garden forms of the red spruce, such as the hanging form 'Inversa', are best used in solitary settings.
Dwarf spruces such as the Igelfichte (Picea glauca 'Echiniformis') are also suitable for planters
Far larger is the assortment of dwarf forms of red spruce and other spruce species. They usually have a ball-shaped to pillow-shaped growth and are often planted in heather gardens or rockeries. In addition, they are popular as a rhododendron companion, as green quiet poles in perennial and rose beds and as easy-care planting for troughs and other planters. Also as grave planting the dwarf varieties of the spruce are very often used.
Important species and varieties
Here is a brief overview of the most important spruce species for the garden:
- Red spruce (Picea abies): The wild species is less popular as a garden plant, but there are a variety of varieties with special growth habit, of which some, such as 'Echiniformis' barely 50 centimeters high. All varieties, like the mother species, have relatively thin shoots and short, fresh green needles.
- Mane Spruce (Picea breweriana): Up to ten meters high and six meters wide, the tree has main branches with hanging branches, making it an extremely elegant appearance.
- Picea glauca (white spruce): The wild species of this North American spruce has no importance as a garden plant, but some breeding forms such as 'Conica'. It is also referred to as Zuckerhutfichte, is about three feet high and forms a dense, sugar-hat-shaped crown with short gray-green needles.
Sugarloaf spruce (Picea glauca 'Conica', left) and hanging red spruce (Picea abies 'Inversa', right)
- Serbian spruce (Picea omorika): Both the wild species and various dwarf forms still have great importance as garden plants. The Serbian spruce is a particularly slender crown with slightly drooping main branches. It reaches stature heights up to 20 meters.
- Oriental spruce (Picea orientalis): The species has very short needles and thin filigree branches. The slender tree is quite loosely branched and grows up to 30 meters high with a width of 6 to 8 meters. Particularly in demand is the breeding form 'Aurea' with yellow budding.
- Spruce (Picea pungens): The Spruce holds what its name promises. The gray-green needles are very thick, hard and extremely pointed. It becomes 15 to 20 meters high and 6 to 8 meters wide. The variety 'Glauca' with steel blue needles is also called blue spruce.
- Purple fur (Picea purpurea): The purple fur remains very compact with a height of six meters and forms a broad conical crown with thin dark green needles.
- Sitka spruce (Picea sitchensis): The North American 25 to 40 meter high spruce species has a slender fresh green crown. It used to be very common as a garden plant, but is rarely planted because of its susceptibility to the Sitka spruce.
The wild species of the spruce are usually propagated by sowing. Collect the ripe cones as soon as they have fallen to the ground, dislodge the seeds and dry them for a few days. Then they are stored in paper bags airy, cool and dark. Before sowing in March, they are allowed to swell for 48 hours in a foil bag with moist sand in the refrigerator, then they are sowed breitwürfig in trays with potting soil or directly into the garden bed and only thinly covered with soil.
In the nursery today, low garden species are usually propagated in late summer by cuttings of new, well lignified shoots.In the hobby garden, however, the method is usually not practical, since you usually need a greenhouse with nursery bed and floor heating and a spray mist system to keep the humidity evenly high.
All higher-growing varieties as well as some wild species such as the mane spruce are propagated by refinement. This is done by lateral plates of the precious rice in late summer to potted, three- to four-year-old seedlings of red spruce. The further cultivation and hibernation takes place in the greenhouse.
Diseases and pests
One of the most common spruce pests is Sitka spruce. In addition to the spruce species of the same name, it also graves Serbian spruce, red spruce and some other species. In contrast to other aphids, it is also active in winter and is easily recognized by its characteristic red eyes. Infested spruce needles are strong. Control is possible, among other things, with preparations containing rapeseed oil, whereby the branches and twigs must be very well wetted from above and below. The treatment should be repeated several times every two weeks.
If the needles of the spruce trees darken for no apparent reason and fall to the ground, a magnesium deficiency may be the cause. It is relatively easy to remove with bittersalt, a special magnesium fertilizer.