With the sour cherry, even a north-facing wall can still bear fruit! Sour cherries are robust, undemanding, and high-yeilding. Annual pruning is necessary to avoid a balding of the branches and trunk. Sweet cherries are almost never a good choice for an espalier fruit tree. They are very hard to train, are often difficult to pollinate, and can be wiped out by birds long before the fruit is ripe. If you want a sweet cherry, free-standing trees trained as tall spindles are much more promising than growing them as espaliers.
Lat.: Prunus cerasus
Sour cherries have no special soil requirements, though heavy, loamy (clayey), and very moist soils are the least optimal. They like semi- shady to shady locations; that is ~ east, west, or even north walls. Sour cherry trees can be found in local tree nurseries or ordered online.
Sour cherries are treated as shaped trees when they are grown on a trellis. Flowers in April / May; fruit ripens in July / August depending on the cultivar. We recommend the new breed "Morello cherry Vogt" ("Vowi"). Important: sour cherry trees are often sold grafted, but for trellising on a smaller wallspace, poor sandy soils, or dry locations, ungrafted plants are more effective, or those grafted on Prunus mahaleb rootstock. For large trellises, heavy (clayey) soil and in damp/humid locations, a bird cherry rootstock (Prunus avium) should be used. Thin out every 5 - 8 years after the crown of the tree is fully established, just after harvest. Lightly pruning all shoots every spring reduces the risk of Monilia infection (a brown rot fungus) by removing spores in the top buds.
Below you will find a table with all suitable trellis forms for sour cherry. Easy trellises in our easy basic or basic-s ranges are good choices for a sour cherry espalier; for larger projects~ the medium, heavy or massive designs should be used. The tree is trained to a fan shape on the trellis, without a central trunk. The trellis should be built as described in the section on shaped trees, with dominant axes 35 - 40 cm apart.