Trees are graceful, long-lived garden features with wildlife-friendly properties. Even so-called “small trees” take up significant space and, realistically, gardens can only accommodate a limited number of them – or even none at all. Happily, hedges and certain shrubs can give many of the benefits of trees in small spaces.
Hedges are trees – sometimes shrubs – planted so close together that they stunt each other by competition for light, moisture and nutrients and are, therefore, easy to keep compact with regular clipping.
Well-chosen hedges – yew, beech and hornbeam for example – need clipping just once a year and can be kept thin to avoid taking up excessive space in smaller gardens, especially if used, as is often the case on boundaries. Do speak to neighbours though before planting though as not everyone will appreciate shared hedges.
Hedges provide cover and nesting opportunities for birds, support other wildlife, shelter the garden, soak up extreme rainfall, provide privacy and also absorb pollutants – an especially important property for urban gardens. Thorny hedges such as Berberis and pyracantha enhance security. They don’t provide the height of trees, but in other ways offer similar benefits.
Tall hedges are bothersome to cut, requiring ladders and platforms. Hedges are best kept to heights that can be handled with feet firmly on the ground. Having said that, long-handled electric pruning tools have useful extra reach where more shelter or privacy is wanted.
Pleached trees are in effect hedges grown at height with bare trunks below. These can be bought ready pruned and trained at a price. They effectively intercept lines of sight-enhancing privacy, but maintenance needs are high.
Best wildlife benefits come from informal hedges of native hawthorn, hazel, spindle bush, guelder rose, dog roses and holly, where shoots are allowed to grow strongly enough to flower and bear fruits which might involve only pruning every other year or even every three years.
Some shrubs verge on being trees and are typically up to 4m-high. Ideally, to be tree-like, they should have a short stem rather than branching from near ground level. Cotinus coggygria, with striking foliage and smoke-like clouds of flowers, and Buddleja alternifolia (with long drooping strands of lilac summer flowers), are examples of deciduous big shrubs that can be trained with short stems so that it is possible to underplant with smaller shrubs, bulbs and ferns beneath.
![Cotinus coggygria [Smokey Joe] = 'Lisjo' (PBR)](https://wp.inews.co.uk/wp-content/uploads/2023/11/SEI_179597039.jpg?w=760)
Small versions of magnolia, including almost black-flowered Magnolia liliiflora Nigra and M. stellata with its white starry flowers, can be accommodated even in small gardens. Frost protection for their large vulnerable flowers is feasible by draping bushes with fleece or hessian on frosty nights in spring.
For evergreens, Ceanothus arboreus Trewithen Blue make colourful large shrubs covered in blue late spring flowers, while Cotoneaster cornubia is full of long-lasting bright red autumn berries while also providing year round greenery and insect-friendly spring flowers.
Although trees, left to their own devices, are often hard to accommodate, they can be manipulated to restrict their size so should not be entirely rejected in small gardens. A spectacular method is to let trees such as Indian bean (Catalpa bignonioides) tree or Paulownia tomentosa grow to about 2m-tall before cutting them back in winter to scout 1.5m. The resulting regrowth is vigorous and although flowering is prevented, the leaves are startlingly large.
Repeated every year the “tree” is kept down. Cercis canadensis Forest Pansy is particularly rewarding with its red new leaves much-enhanced by severe pruning in late spring.
