Construct the espalier, for example with tree posts, so that three posts in a row (interval 250 centimetres) have a height of two metres above the ground. Along these posts, stretch wires at four different heights, one every 50 centimetres.
Place the blackberry plant against the middle of the espalier. Leave four shoots from the budding of the plant and bind one each to each wire level. Clip the tip of the shoot if the cane is longer than 250 centimetres. If the cane branches off, prune the side shoots to three buds in early spring.
While flowers and fruits appear on these shoots, the young shoots sprout from the ground. Fix these as described to the wires of the espalier side which has been kept free. After the harvest, you remove the stripped canes down to the ground and thus have a free espalier side for the young blackberry shoots of the coming year.
With this so-called espalier training, you ensure that fruit buds and young shoots do not grow in a disorderly way. This facilitates the harvest, the overview for the necessary pruning, and improves the health of the plants, as dense, insufficiently drying foliage inhibits ripening of the fruit and tends to lead to infestation with grey mould.
Tip: When fully ripe, blackberries have achieved their best aroma. However, they are only fully ripe when they can be very easily detached from the branch, when they easily fall into your hand. Therefore, an already black-coloured blackberry may still taste sour if you pick it before it is fully ripe – the visual impression of the ripeness of the berry may be very deceptive here! In addition, the sweetness of the berry depends greatly both on the variety and on the intensity of sunlight.