It’s all a matter of balancing the outrageous show-offs with the quiet achievers, says Jo Arnell.

Garden borders can be tricky to get right. ‘I’ve looked at borders from both sides now,’ Joni Mitchell might have sung, had she been keener on gardening. If you’ve looked at yours in all weathers, in all seasons, from all angles and still somehow, you really don’t know borders at all, have one last look before chucking in the trowel.

When we go to the garden centre to buy plants, we tend to fill our trollies with all the gorgeous flowering beauties that have been put at the front of the display, because they are looking their particular best at that particular moment.

We rush happily home with our beautiful haul, plant them out and – and well, they either disappear into the existing scheme (in some cases never to be seen again), or they just don’t seem to hang together. There are many reasons why this could be happening, but the most obvious, the topiary elephant in the room if you like, is a lack of structure.

Borders need structure, focal points and boundaries in order to show off their best attributes. There has been a fashion in recent years to plant swathes of perennial plants, which is lovely, but many of them are lax in habit, tending to sprawl about lacking definition and impact.

A whole summer border full of delicate wispy plants can easily look like a jumbled mess, but put a well-placed, dense-leaved and formal-looking evergreen amongst them and – like putting a teacher in a classroom – the whole space comes together and magically appears to be more ordered.

Whole gardens and large borders need relatively large structural elements – trees, big sculptures, garden buildings etc – but even small spaces benefit from these. Large plants work well in small spaces too, in fact small plants in small gardens often have the effect of miniaturising the space, which isn’t always a good look. It’s all about scale and proportion.


Hedges, paths and walls are the boundaries that keep the plants corralled, providing a pleasing edge to the planting and containing the plants with edges. Hedges separate areas, bringing definition and lots of structure.

A hedge provides a textured, but uniform green backdrop, fulfilling what hard landscaping does in design terms, without being hard in the slightest. The wind-break job they do is far more effective than a fence or wall too, because the wind is slowed down by a hedge, not stopped in its tracks – where it’s left with no option but to go up and over and then create turbulence in the borders on the other side.

Choose a hedge to suit your garden. The clipped formality of a yew, beech or box hedge is used to good effect in formal gardens, whereas a more relaxed, informal line of shrubs or hedging plants such as a flowering Rosa rugosa, Choisya ternata, or Escallonia will give a structural backdrop and some seasonal interest.

Hedges can take time to establish, it’s true, but after a couple of years most hedging plants grow away really well. Depending on the species, they will need regular pruning to keep them looking tidy.

Focal points

Focal points act as anchors, pinning down the wavering and the blousy, providing a resting point for the eye and drawing you further into the garden or border. Too many, or ill-placed focal points have a jarring effect, detracting from one another.  It’s the same with a beautiful view. Use plants to lead the eye toward it and then frame the view, not obstruct or compete with it.

There are some structural plants that just won’t stand in a line, in fact they won’t be told what to do at all and need to be the centre of attention all the time. Putting a horticultural exclamation mark, like a Yucca or a Phormium, into the shadows, or tucking it at the back of the border will make you both uncomfortable, they need the limelight, with the emphasis on light.

Use architectural plants sparingly too. Planting another attention seeker too close will cause a fight. Focal points work best either on their own, or among less defined shapes that will provide a foil or a background for the showier plant.

Rhythm and punctuation

A focal point that attracts attention, but in a calmer way, will bring useful contrast and punctuation within the border. This works effectively in the winter, but also at other times of the year too. A neatly clipped box ball or other small-leaved dense evergreen (even a stone ball or an ornament) will act like an anchor and bring order to the space, and if you use more than one, will set up a rhythm.

If you haven’t the time or patience for clipping box (I love it – do it in early summer when the birds are singing and your freshly sharpened shears are gently clip-clipping, it’s a Zen activity), there are plenty of naturally neat evergreens that will do the job almost as well.

Low-growing Hebes like H. ‘Red Edge’ or H. ‘Sutherlandii’ will sit like dense little puddings in the borders, unchanging all year. They hold their shape well, quietly expanding over the years into large low domes.

Slightly taller, but slow growing, Viburnum davidii is a wonderful plant – one of my absolute favourites. It has large, deep green, slightly ribbed leaves that are glossy and handsome. It is well mannered and slowly grows into a tidy domed shape all by itself – no pruning needed. If the Hebes are puddings, Viburnum davidii is the queen of puddings.

Many really useful structural plants get completely overlooked in favour of glamorous show-offs because they’re not spectacular in any way; their job is to provide the wind beneath the wings of the divas and the spineless.

I’m always trying to champion these overlooked and unsung stalwarts – they are often found in supermarket plantings, where they are badly treated and end up as amorphous lumps and weird cubes.

The reason they were chosen for such places is because they are so good natured; putting up with poor soil, used to being hacked at, driven into and swamped with exhaust fumes. Allowed to show their natural beauty in the balmy garden borders they come into their own and reward us with their low maintenance and quiet good looks.

I’m particularly fond of Cotoneaster horizontalis. Its stiff herringbone stems will spread slowly up walls, or into arching mounds if gently encouraged and will reward you – and the birds and bees with blossom, berries and brilliant autumn colour.

Then there’s Photinia ‘Red Robin’, which has become ubiquitous and can be a bit boring if left to its own devices or wrongly pruned. It is evergreen, but given a bit of care, will warm the garden in early spring by putting forth glamorously shiny, bright red leaves. Mahonia is another handsome evergreen with leathery, mildly aggressive foliage and spectacular, highly scented flowers that bloom like spikes of sunshine in the darkest of winter days.

Plants need to pull their weight in the border and there should be no space for slackers. Structural plants are strong and reliable, lynch pins, carrying the border through the seasons and linking one part of the garden to another. All the other plants will be relying on them. Keep them well tended, fed and healthy and they will reward you for many years.

Contact Jo for details of 2019 gardening courses

01233 861149

Structural plants don’t all have to be evergreen, but must have a presence and be of sufficient size not to be swamped by other plants in the border. Evergreens provide a constant look and will ensure that the border looks good through the seasons, even in the depths of winter.


Phormium tenax (good strappy foliage)

Camellia japonica (glossy leaves)

Euphorbia characias (bracts and foliage)

Elaeagnus x ebbingei (a good evergreen anchor)

Abelia grandiflora (autumn flowers)

Arbutus unedo (long season of interest)

Osmanthus burkwoodii (dense, small leaved)

Viburnum tinus ‘Eve Price’ (flowering evergreen)

Viburnum davidii (large deep green leaves)

Fatsia japonica (large, glossy, palmate leaves)

Pittosporum (dainty variegated leaves)


To be effective structural plants the deciduous shrub layer should have a good overall shape and more than one season of interest, ie autumn colour, berries or strong architectural form

Cotinus coggygria ‘Grace’ (fantastic foliage)

Cornus – either flowering, or stem interest types

Cotoneaster horizontalis

Spiraea japonica ‘Goldflame’ (good spring and autumn foliage)

Hydrangea (long lasting bracts)

Berberis (dark red leaves, good autumn tints)

Sambucus nigra ‘Black Lace’ (dark leaves, blossom)

Melianthus major is a surprisingly hardy exotic architectural anchor plant

Phlomis russelliana is a herbaceous structural plant

Phormiums provide striking border structure

Phormiums provide striking border structure

Yew topiary focal points at Great Dixter

Yew topiary focal points at Great Dixter

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