Sarah Morgan discovers which trees work best for small gardens
A garden, however small, needs a tree. It offers shade, changing interest all year from buds, flowers, leaves, fruit and bark, and in urban settings can offer huge environmental and health benefits. But which one is best for which garden?
A good starting point is the favourite small tree of garden designer Sara Jane Rothwell MSGD - Amelanchier x grandiflora ‘Robin Hill’ AGM, which has all the qualities of one of our prettiest shrubs, Amelanchier lamarckii AGM, but in an upright tree form with a clear stem. Unlike the shrub, the flower buds are a delicate pink.
As well as this, Rothwell likes to introduce woodland into the city with copses of native trees. “In nature, silver birch grow closely together and also get quite tall, so are excellent for screening, as in urban gardens it’s all about creating privacy,” she explains.
Perfect for pleaching
Birches also bring contrast to the formality of the pleached trees Rothwell often uses. She regularly specifies these hedges on stilts along garden boundaries, for added privacy. “They don’t take up much volume yet create another instant 2m of greenery above the legal fence height of 2m. I’ve even had clients’ neighbours complain to councils that the newly planted fence is too high, but you are allowed to do this as they are trees on a framework.”
When it comes to finer design details, Rothwell often uses large pieces of Corten steel against pleached Liquidambar styraciflua ‘Fastigiata’– “one of the best autumn-coloured trees”. She also finds this tree reliable in London clay soils. “I love the lightness of deciduous trees like this as they create a dappled light and embrace the magic of spring when the new growth appears.”
Best winter bark
Tom Wilson, sales executive at Barcham Trees, favours several more unusual trees perfect for small spaces. For winter bark, he recommends Betula ermanii. “I’ve got a small terraced garden and this is a beautiful addition,” he explains, “as it doesn’t cast too much dense shade and tolerates most conditions. Birches are always popular for both these reasons, plus their stem colours are especially important in winter when there’s not much else happening. This has peeling bark in cream with a pink tinge and reaches a mature height of 15-20m with a spread of 4-8m.”
Should be grown more
One tree he feels should be grown more is Koelreuteria paniculata ‘Fastigiata’. Commonly known as Golden Rain or Pride of India, it was raised at RBG Kew from seeds received in 1888 from Shanghai. “I think it should be more popular, as it’s both an unusual and interesting tree. It has yellow flower panicles that the bees like; it’s drought tolerant; and the lantern-shaped fruits in autumn are wonderful.” It reaches an eventual height of 5-10m, with a spread of 1.5-3m.
Urban tree picks
For hot, urban gardens, Tom believes Lagerstroemia indica ‘Rosea’ AGM is the right choice. “When the nursery first started growing this tree in the late 1980s, it was treated as half-hardy and never flowered, but now it flowers regularly, so with our warming climate it is ideal, as it really likes a baking suntrap. Its flowers come out late in October and are unusual – they look like crepe paper. But what I really love is its exceptional bark colour; it’s really pale and creamy, as if the stems have been skinned.” It grows to 5-10m high with a spread of 4-7m.
For foliage colour, try Malus toringo ‘Scarlet Brouwers Beauty’. “This is a beautiful new, compact crab apple – perfect if you don’t want to make a mess of paving, as the fruits are smaller than a Malteaser. It’s a great small tree for foliage contrast, as the leaves are purplish-red turning to dark green as the season progresses. It also has dark-pink spring flowers. Whereas most Malus have simple leaves, I find these lobed and serrated ones much more interesting.” It has a mature height of 3-8m and a spread of 2-4m.
The top choice for evergreen screening is Osmanthus armatus. “These days people often need evergreen screening that is raised to block out a neighbouring property or road. This is a new one that we really rate – the autumn flowers are scented and the leaves are really lush and green. We sell them as standards with tightly clipped heads, which you can either keep by pruning, or allow to grow for a bigger canopy. It’s hardy in the south and middle of England.” It has a mature height of 3-5m with a spread of 2-4m.
Best flowering tree
Syringa reticulata ‘Ivory Silk’ is the best pick for flowers. “Clients always ask for shrub lilacs,” says Tom, “but they don’t realise what excellent small flowering trees they make. This is a recent introduction from Canada that flowers when most trees have finished in spring, extending the season with ivory-white scented flowers in June and July. It grows to 5-7m with a spread of 3-5m.”