Hedges are not only a design element and aesthetic enrichment of the garden and the cultural landscape, but also fulfil numerous other tasks: For example, they improve the microclimate, filter dust and exhaust fumes from the air, dampen noise and provide privacy. They are also a valuable habitat for numerous animals. Bird hedges also contribute to the ecological balance in the garden in agriculture by attracting beneficial insects that, for example, keep pest pressure down or ensure the pollination of fruit trees. Above all, they are an important habitat for birds: as a singing place, as a nesting place, as protection against enemies, wetness and cold, and as a source of food.
What grows in bird hedges? Native shrubs that promote biodiversity
The choice of hedge shrubs is of great importance if you want to use them to support wildlife. Unfortunately, most gardens are stocked with exotic shrubs. And these ornamental shrubs often reveal a problem: they offer little usable food for native wildlife. Either they have become barren due to cultivation, like the ornamental cherry and the double snowball, or their fruits hardly ripen in our climate, like the rhododendron and the false hazel. Even if the exotics produce fruit, they are often not utilised by the native fauna. In contrast, our native shrubs provide for far more animals. No wonder, because in the millennia of evolutionary history, native animals and native plants were able to optimally interact with each other.
A few examples illustrate the great ecological benefit of our wild shrubs: the fruits of the native hawthorn are eaten by 32 bird species, while the related exotic scarlet thorn is used by only two species. The native juniper feeds 43 bird species, whereas the Chinese juniper, which is often planted in ornamental gardens, has only one consumer, namely the chough, which does not occur at all in our gardens.
The situation is similar with the popular ornamental shrubs deutzia, forsythia or weigelie, which are also only visited by one bird species. In a rhododendron or thuja hedge, not a single bird will find anything to bite on. In contrast, more than 60 bird species feed on the wild rowan or black elderberry, and many mammals also nibble on the valuable fruits (see the top ten for bird life below). Our native barberry is visited by 19 bird species, while only seven birds like the red-leaved Thunberg barberry. The situation is similar when comparing red dogwood (24 bird species) with white dogwood (eight bird species).
Bird hedges also help insects
What is true for birds is also true for the insect world, because more insect species live on native woody plants than on exotic ones. Numerous aphids, beetles, wild bees and butterflies depend on the flowers and leaves of shrubs. Willow, hawthorn and blackthorn, for example, are each an important food source for over a hundred insect species. 77 small butterflies alone visit the saltwill (see the top ten for the insect world below). However, butterfly caterpillars are hardly interested in ornamental shrubs: the popular summer lilac, for example, is completely worthless as a caterpillar food plant, although the finished butterfly is then quite happy to suck the nectar from the pretty flowers. There are no comparative studies here in Europe yet, but in the USA, 15 times more butterfly species have been found on native shrubs.
The number of insects has drastically decreased by 80 percent in the last decades, so that today one speaks of an insect extinction. Of course, this also has an impact on bird life, which feeds mainly on insects. Thus, the number of breeding pairs of birds has also declined in recent years: In just 12 years, Europe has lost 12.7 million breeding pairs!
Bird hedges are also great for gardeners: However, our wild hedges are not only more ecologically valuable, but also much less demanding and more resistant. They are adapted to local conditions and are more robust against cold and pests. Moreover, native shrubs can be had very cheaply in nurseries.
Planting bird hedges correctly: This is what you need to bear in mind
The best time to plant all deciduous shrubs is in the autumn months of October and November or in early spring from March to April. Only the evergreen shrubs should be planted in late summer (August, September) so that they can take root before winter.
Plant the individual shrubs about 1.5 metres apart. The planting hole should preferably be twice as large as the root ball of the shrub. The shrub is now placed in the hole and loosely filled in. It makes sense to add a little compost. After planting, water the shrub with plenty of water and tamp down the soil well in the planting hole. Weak-growing shrubs and small shrubs are best grouped together (3-4 plants) and planted at the end of a hedge so that they remain competitive. These include, for example, sloes and hawthorns.
Care of a bird hedge: This is what matters
A natural hedge cannot do without maintenance, which is why it should be regularly pruned back every 1-2 years. After about 5 years, it should be pruned back to the old wood. For shrubs that tolerate pruning (e.g. hazel, hornbeam, privet), radical pruning is possible: they can be “put on the vine” about 30 centimetres above the ground. However, only individual sections of a hedge should be cut back so that sufficient hiding places remain for the animals. There are also some legal requirements regarding the time of pruning (see above).
Which shrubs belong in the bird hedge? Clearly: it’s the mix that counts
The more species-rich a hedge is, the greater its ecological value. Wide hedges (5-8 m) planted in two or even three rows are particularly valuable. This is where many more animals can be found, as wide hedges offer more cover than single-row narrow hedges. Thorny hedges (barberry, hawthorn, blackthorn, wild rose) are particularly popular with birds as they provide cat-proof hiding places and breeding opportunities. A natural hedge also includes shrubs of different heights, and in large gardens there may well be room for a tree. The bird cherry, for example, is very popular with birds and bees.
In a natural garden it makes sense to enhance the hedge with further measures. This includes leaving the withered leaves under the hedges in autumn or possibly raking them into small piles. This creates hiding places for numerous small animals. The robin only settles where layers of fallen leaves provide them with a sufficient food supply. Cut and broken wood can also be piled up in some places in the hedge and serve as hibernation facilities for garden animals (e.g. hedgehogs, toads, shrews, slow worms).
A species-rich hedge is a treat for the eye with its different flowers and leaves. In addition, numerous wild fruits are not only useful for birds, but also enrich our diet (see Top Ten for human nutrition). Wild fruits contain an extraordinary amount of vitamins and minerals. For example, the fruits of wild roses have about 20 times as much vitamin C as a lemon.
Tips for selecting woody plants for the bird hedge
Since some of the bird trees are poisonous to humans, they should not be planted near playgrounds and kindergartens. These include, for example, the very poisonous peony and yew as well as the slightly poisonous species privet, honeysuckle, black alder and buckthorn. In this context, it must be pointed out that numerous exotic ornamental shrubs are also very poisonous, e.g. cherry laurel and laburnum.
Some shrubs can be carriers of diseases. Therefore, hawthorns, wild pears, mealberries and rowan berries do not belong near fruit and walnut trees (fire blight). Juniper should not be planted near pear trees (pear lattice rust) and barberry does not belong near grain fields (grain black rust).
When selecting shrubs, it is important to take into account the different site requirements in terms of soil, moisture and sunlight. Common snowball, peony, weeping cherry, black alder and willow tend to prefer moist sites, while dog rose, cornelian cherry, sea buckthorn, hawthorn, blackthorn and rowan prefer dry sites. Barberry, privet, snowball, sloes, buckthorn and wild roses are particularly lime-loving.
Bird hedges: habitat and food source: Top ten at a glance
Top ten hedge shrubs for bird life
In brackets you can see how many bird species visit the plants.
Rowan (63), Black elder (62), Elder (47), Common juniper (43), Black alder (36), Hawthorn (32), Wild blackberry (32), Dog rose (27), Red dogwood (24), European peony (24)
Top ten for insects
In brackets you can see how many insect species visit the plants.
Willow (213), Hawthorn (163), Blackthorn (137), Hazelnut (112), Wild Rose (103), Wild Blackberry (85), Blackthorn (45), Buckthorn (45), Red Honeysuckle (40), Red Dogwood (32)
Top ten for human nutrition
The order of this top ten is rather random. All wild shrub fruits are an enrichment for our diet.
Wild rose (rosehip), sea buckthorn, rowan, black elderberry, hazelnut, wild blackberry, blackthorn, barberry, cornelian cherry, black cherry.