We want a shrubbery!
“We want a .. shrubbery. One that looks nice, and not too expensive.”
It is hard to be asked for a shrub border without recalling this unusual request from the Knights Who Say ‘Ni’ in Monty Python’s Holy Grail. However, I would perhaps query the knight’s horticultural intent as I would rarely devise a planting plan entirely based on shrubs when combining them with other plants that offer either different seasons of interest or textural contrast works better.
Shrubs have a valued role to play in many gardens, often as a year-round backbone to more dramatically changing perennial or bulb planting. There are also many that have fabulous blossom, both for colour and wildlife, and rich autumn foliage colour. But it is worth bearing in mind that shrubs will, in general, grow much more slowly than perennials and they are much harder to move once established, so their use and placement require greater planning.
One of the key issues to remember when choosing shrubs is that they are often bought very young and growth rates differ enormously, so you need to think carefully both in terms of their eventual size, which can be as large as a small tree, and the level of patience you have in waiting for them to reach maturity. The smoke bush Cotinus coggygria, for example, might be bought at a foot or two tall but given the right conditions you could see two feet of growth in the first year or so and it will become hard after several years to keep it much smaller than six to eight foot tall – left unchecked they can grow into small trees.
Conversely, a Hebe bought at nine inches tall might take ten years to fill a one metre wide space in your border by which time the garden may have evolved so much that the Hebe is less relevant; or you may have lost patience after years of weeding around the young plant so you decided to replace it with some fast-growing perennials. When choosing your shrubs look twice at the variety or cultivar – experienced nurseryman looked aghast last year before our efforts to remove a dying Hebe, which everyone thinks of as dwarf shrubs, that was more than seven feet wide. Hebe pinguifolia or vernicosa are dwarf varieties that should reach no more than two foot in height and three foot wide but Hebe salicifolia can get to more than six foot tall.
So, what are my favourite shrubs? Well I am quite particular with shrubs – as flowering season can be short, they must offer something else throughout the year, whether that is overall form, leaf shape or autumn colour. Shrubs such as the dogwood Cornus do offer vibrant stems in the winter but they are a bit of a formless green blob for much of the rest of the year so I would tend to use these only in a winter garden. Where you are creating a mixed border combine different sized shrubs for strongest balance – so perhaps at the front of the border you might use a ground cover rose such as Scented Carpet, a Daphne odora so that you can appreciate the scent, or rounded shrub Pittosporum Tom Thumb with its plum glossy leaves. In the mid-border you might juxtapose the arching branches of bottlebrush plant Callistemon with the flat spread of Cotoneaster [RK1] horizontalis or the vertical stems of Berberis thunbergii Helmon Pillar. Towards the rear you might consider using the copper-red foliage of Physocarpus Diable D’Or as the perfect foil for the pale pink flowers of Echinacea purpurea or the lilac tones of Achillea Apple Blossom.
Wherever you plan to use shrubs, aim for maximum contrast, varied flowering season and a mix evergreen and deciduous. Then try combining them in unexpected ways with bulbs, ornamental grasses, perennials and roses.
You can contact Robert Kennett on 01747 858215 or via his website robertkennett.co.uk