Trellis
A trellis (French espalier , cf. possibly Italian: spalla = support, shoulder) is a mostly grid-like construction to which traditionally useful plants ( fruit tree shoots , vines ) can be attached and brought into a desired growth shape. In the distinction to a climbing aid or a trellis , on which climbing plants grow up independently, various non-climbing plants or their shoots are regularly tied to a trellis. Espaliers are also used for ornamental plants (e.g. roses ) or even without plants (as a pure ornament ).
A trellis can be attached to a house wall or built as a free-standing construction. Espaliers can be made of wood , metal , wire or fiber composites, e.g. B. glass fiber reinforced plastic can be built.
A freestanding trellis is also known as a pergola .
history
In horticulture, espalier ( espalier ) originally meant the cultivated form of espalier fruit, also called fruit hedge ( palissade ). It originated in France at the end of the 16th century. The fruit hedge could stand against a wall or stand free. In the latter case one spoke of contrespalier . In the 16th century, no wooden scaffolding was used, but only kept the fruit hedges in shape from the outside and tied them to the wall in a makeshift manner. The term espalier (espalier) originally had nothing to do with lattice frames. There was also no special cutting technique. The trees grew largely free within the hedge.
In the middle of the 17th century, espalier fruit appeared en eventail in France . This means that the trees were directed into a certain, fan-shaped shape.
In the middle of the 18th century, René Schabol drew attention to a newly developed espalier tree shape in Montreuil (Seine-Saint-Denis) , in which, as with the dwarf tree, the main shoot was removed and only two branches that rose at a 45-degree angle were left. from which the branches went off approximately vertically and horizontally. This shape - also called palmette à la Montreuil or palmette quarrée - appeared more geometric than the previous ones . Like the fan, it had actually been developed for the peach, but was even better suited for pear and apple trees.
Espalier trees with branches that are exactly vertical and horizontal ( palmette à cordon horizontal ) first appeared in the Netherlands and England in the 18th century. This more elaborate form of espalier fruit made it possible to use vigorous pear varieties, which in this way could probably take up ten meters of a wall. Allegedly only they guaranteed the even distribution of the juice on the trellis.
Many other forms of espalier fruit emerged in the 19th century, including:
- The candelabra palmette (palmette -candelabre ) with vertical branches that leave from a low, horizontal branch
- U-shapes ( cordon vertical )
- U-palmettes, where the tree is divided into one to four U-shapes that are lined up next to each other
- The Verrier palmette with concentric U-shapes of decreasing size, named after Louis Verrier, a horticultural teacher who developed it around 1850
- The palmette with oblique branches (palmette à branches obliques ) and
- Oblique cordon ( cordon obliques )
Construction forms
The lath and wire work, on which vines and fruit trees are stretched and tied with the branches and twigs, can preferably be attached to walls or house walls that are oriented to the south . Special wooden posts are used for the load-bearing structure, which are also known as stickels in viticulture . Is on the trellis with wire hooks a plasticized or a simple galvanized iron wire fixed via a clamping Stickelberger at the beginning of the line and at the line end of a trellis and a bar anchor is stretched taut. Re-tensioning is carried out using a turnbuckle or special stitching chains . The tensile load can be very large depending on the crop, training method and line length on the wire and stick used. At particularly stressed areas in the trellis, crossbars can therefore be attached between the sticks in such a way that the tensile stress is dissipated into the ground. On the tensioning stick, which has to bear the greatest tensile load, in addition to the rod anchor, the use of a wedge wood is recommended , which transfers the forces evenly into the ground via the two following trunk sticks.
application
Fruit growing
Espaliers exist especially in fruit growing and also in the open field to give the trees a shape suitable for harvesting. These espalier trees differ from pyramid cultivation in the position of their branches, which do not stand in a spiral line around the trunk, but rather in pairs, as far as possible opposite each other on the right and left, forming the most horizontal guide branches possible. This cultivation method, specially designed for the use of harvesting machines , makes it possible to drive through the rows of space-saving espalier fruit (a type of shaped fruit ), but it is associated with numerous disadvantages for the useful plant. The linear alignment makes the systems particularly susceptible to wind . The uniform distances between the crops and the wide reading alleys lead to the soil drying out more quickly and increasing its tendency to erosion . To avoid drought stress , plants on such trellises often have to be artificially watered .
Viticulture
- → see main article vine training
Floor education with vines on wooden slats - historical illustration.
Espalier vines on the southern front of the educational institution in Geisenheim / R. - historical illustration.
Vineyard with trellis training in South Tyrol.
Other meanings
A trellis is also used to describe the formation of troops or people in rows on both sides of a route. Such an alley made up of two rows of standing people and / or mounted animals (standing in a trellis) is created to honor special people or on special occasions such as weddings, christenings or deaths, as well as for punishment ( running the gauntlet ).
The growth form of certain alpine plants called espalier growth was also derived from this structure.
literature
- Marina Heilmeyer, Lutz Grope, Gerd Schurig, Clemens Alexander Wimmer: Best pears at court. Potsdam pomological stories . Vacat, Potsdam 2004, ISBN 3-930752-29-8 .
- Klaus Wallach: Des arbres fruitiers élevés en espalier or: The art of trellis construction in the 2nd half of the 17th century . In: Die Gartenkunst 1 (2/1989), pp. 193–205.
