This form is particularly suitable for narrow, vertical areas and/or if the quality of table grapes is to be very high. What may look rather rigid and somewhat unnatural at first glance, soon enough surpasses any other "free" espalier form: there is no tedious sorting of shoots; pruning becomes a routine and the stem framework remains very manageable.
This training method most likely originates from France and was described in Germany by Hardy / Jäger in their work "Obstbaumschnitt" ("Fruit Tree Pruning") as "Herzstamm" ("Heart Stem") in Erfurt in 1855.
Not including the planting area, each cordon needs a wall area of approx. 0.6m x 1m, max. 1.5m x 2.5m. For wider areas, several vines are planted, spaced at approx. 1.5m centres. For high walls, several cordons are trained to staggered heights (see diagrams below).
These require a vertical wire rope, but better three wire ropes (spaced 30 - 40cm apart) to allow young shoots to twine or be tied to wires on both sides. For very narrow areas, use 2 wire ropes and guide the shoots to one side only (see photo). Timber trellises are suitable as well.
Refer to diagrams. The yearly vertical extension is about 50 to 80cm; i.e, approx. 4 new side shoot positions. In the end, there will be max. 8 - 12 side shoot positions or a max. distance of about 2m between the lowest and highest canes; otherwise, the lower shoots will fail. The trunk will end approximately 50cm below the top of the trellis. Once the training is finished, spur pruning follows. Ideally the green shoots are either tied to or tucked behind the single/two outer wire ropes. The uppermost side shoot position requires Rod Pruning, because growth is very vigorous there. At a later stage and over the course of 2 - 3 years, switch to cane pruning of several side shoot positions (see diagrams below), starting from the uppermost cane down to the lowest, leaving only about 4 - 6 side shoot positions per cordon and increased distance between the individual tiers...to be followed by summer pruning if necessary.