Do you have only a small property and would really like to harvest fruit? Or are you keen to grow a particularly delicious apple species, which you remember from your grandfather's garden, and which is not available commercially? In both cases, espaliers offer the answer, as they are grown along the house or a wall.
How come that espalier fruit grows so well? Because a sunny wall creates conditions which usually occur in the warmer southern climates only. A wall provides protection from the wind, hence the accumulated warm air is retained, which in turn benefits the plants. Many fruit species love these conditions, provided that they are also watered regularly.
If you intend to grow winter-bearing fruit espaliers, you will also need to provide adequate storage facilities and conditions!
Generally, grapevines, pears and peaches love full sun exposure, even during midday, hence they need to be planted along south- to west-facing walls. However, apples, cherries, plums and apricots do not like to be "cooked to maturity" in this way. They quickly loose their aroma and characteristic fruit acid. Furthermore, apricots will flower too early and then risk being affected by late frosts. Therefore, a semi-shaded position along a house wall is usually sufficient. However, less fussy summer pears and cherries even thrive on shady north walls. In summary, the following classic fruit species can be cultivated along walls and have been listed in decreasing order of their requirements for position: late Grapevines, (late) winter pears, late winter apples, peaches, late autumn pears, winter apples, early grapevines, plums, early autumn pears, autumn pears, apricots, summer pears, sweet cherries, summer apples, morello cherries.
At higher altitudes and in regions where pears don't usually grow, espalier cultivation offers the enthusiast an opportunity - apart from cultivation in a plastics tent or glasshouse - to grow less demanding fruit varieties. In fruit and wine-growing regions, however, excellent pears for storage can be cultivated on espaliers, ie pears which usually grow in warmer climates only and which may not be commercially available.
Espaliered pear trees used to be shaped in many tiers of strictly angular, geometric forms, so-called "palmettes." Their young shoots are easily trained into simple forms. However, training a pear espalier is complex and takes years, hence it is rarely described these days. We recommend that the interested enthusiast consult old gardening books. Nowadays, the free fan form is more popular due to the reduced maintenance.
For the purpose of pollination, it is essential that there are other, simultaneously flowering pollinator species in the vicinity, ie within a distance of up to approx. 200m. Gardening books and guidelines describe the right pollinator species ("pollen donor") for every pear variety. This is a very important issue especially outside fruit-growing regions. Furthermore - and possibly making this even more difficult - is the fact that one pear espalier variety may be flowering earlier than its intended pollen donor in free cultivation, which means that the desired synchronisation of flowering times may not occur at all. To avoid such risks, it is definitely recommended to have several varieties of pear trees in the neighbourhood rather than just the one variety.
As important as the pollination is the art of pruning, which often varies from one species to another. Some very good old books and guidelines on fruit varieties (e.g. "Pear Species / Apple Species" by Herbert Petzold, for the area of former East Germany), describe concisely which shoots or branches on each fruit tree species bear fruit and how they are to be pruned.
When buying plants, make sure that the future espalier pear is grafted as a vertical cordon and comes with the appropriate certificate. You can either buy plants already trained as small espaliers, or mail-order from specialist tree nurseries. Many nurseries even offer espalier pears (and apples) with double grafts which ensure pollination. Being stingy when buying espalier trees is definitely not worth it and will take revenge!
In urban residential areas, where ornamental juniper is grown, there is a strong possibility that pear espaliers will be affected by the juniper-pear rust, a fungus which uses juniper plants as an intermediate host. It will reduce the affected leaves' ability to assimilate, although it will not affect the fruit. Nevertheless, from an aesthetic perspective the fungus often means the death sentence for the pear tree... In a nutshell: espalier pears are definitely a challenge for the enthusiast!
Peach trees are not as easy to train into angular shapes, hence they are grown and attached to the trellis in a more freely growing fan shape. Often the shrubs are simply planted in front of a warming wall, without any support. Select the trees with their ripening time in mind and remember that grown along walls the fruit ripens approx. 2-3 weeks earlier than the same species in free cultivation. This is important to know and keep in mind, otherwise the fruit may rot just while you are away on holidays....
Most apple species grown as wall espaliers do not necessarily develop better fruit than the ones grown in free cultivation, however if space is restricted, they are easy to cultivate along the house. There are also very special espalier apple species available, which once upon a time were a much sought after and expensive treat, such as the "White Winter Calvill."
It is certainly possible to grow particularly beautiful and large apples on espaliers, provided their ripening process is regularly checked and the fruit yield on the tree is thinned.
In general, the cultivation of apples is basically the same as for pears, see above. Unfortunately, many of the old apple species are unsuitable for espaliers due to their susceptibility to mildew, especially if spraying with herbicides is undesirable. As an alternative, we recommend to investigate the new RE-species from Pillnitz/Dresden, which are resistant to multiple diseases.