Examples of species used as Outdoor deciduous bonsai trees in the UK
You can try to bonsai any tree species, some are easier than others and many people start with deciduous tree species when looking for a bonsai tree to keep outside in the UK. You can use native species like Oak and Elm or look at more ornamental species like Maple. Whatever you choose you will have fun learning the techniques for that species.
Maple (Acer) – and a wide variety of maples make excellent bonsai particularly the Japanese maple, Acer palmatum and some of the cultivars.
Birch (Betula) – not widely used as bonsai but there have been some good examples of Silver birch, Betula pendula as bonsai.
Hornbeam (Carpinus) – commonly used as bonsai and particularly the Korean hornbeam, Carpinus turczaninowii as this has a smaller leaf size already than the european hornbeam Carpinus betulus.
Hawthorn (Crataegus) – another excellent tree species for bonsai with a very rugged winter image but with many features of interest throughout the year with flowers, fruit and thorns and good tracery. The most common hawthorn used is Crataegus monogyna but the red flowering hawthorn is also used.
Beech (Fagus) – The most common beech seen in bonsai to date is the Japanese white beech, Fagus crenata with its stunning white bark. However many people in the UK are now working hard to improve the European beech bonsai trees, Fagus sylvatica as it is widely available as a hedging material.
Ash (Fraxinus) – This is a species that many have tried as bonsai but the common Ash, Fraxinus excelsior has not proved to be overly successful and is now currently a species not advised for bonsai due to Ash die back restrictions.
Oak (Quercus) – a species that takes a long time to develop in a bonsai pot so if you are starting out from an acorn then would be worth considering the size of bonsai you want and in how long. They do make good deciduous bonsai trees but starting with an already developed trunk does aid with the speed of development as a bonsai. They can also be prone to a range of pests and problems like Oak leaf mildew, woolly aphid, and scale but these issues can be overcome.
Elm (Ulmus) – a great choice for anyone who wants a bonsai whether you start with a Chinese Elm, Ulmus parvifolia or English Elm, Ulmus procera. Elms generally have a small leaf size so leaf reduction is less of a focus and they are prolifict growers.