Best Plants for the Back of a Border

The back of a border does the quiet, structural work that everything else depends on. Get it right and your entire border has a framework — height, depth, a backdrop that makes the plants in front of it sing. Get it wrong and the border feels flat, exposed, and like it's missing a wall behind it.

Most people under-plant the back. They fill the middle and front with colour and leave the rear thin or empty. Then they wonder why the border looks good from certain angles but feels see-through from others. The back layer creates the canvas that everything else is painted against.

Here's what works — and what each type of back-of-border plant actually does for the scheme.

What the Back Layer Needs to Do

Back-of-border plants need height — typically 100cm and above, with many reaching 150–200cm. They need to screen whatever's behind the border, whether that's a fence, a wall, or the neighbour's shed. And ideally, they need to provide interest even when the flashier mid-border perennials have finished flowering.

The best back-of-border planting combines two types: evergreen structure that holds the line year-round, and tall perennials or grasses that add seasonal height, movement, and texture. Together, they create a backdrop that works in every month — solid enough in winter, dynamic enough in summer.

The Best Tall Plants for the Back of a Border

Miscanthus (ornamental grasses)

If you plant one thing at the back of your border, make it miscanthus. Varieties like 'Gracillimus' and 'Malepartus' reach 150–200cm by late summer, producing feathery plumes that catch the light and move in every breeze. They create a soft, natural screen that works beautifully against a fence or boundary. In autumn, the foliage turns golden. In winter, the standing stems and seed heads look architectural against grey skies. Cut the whole lot down to ground level in late February and it comes back fresh every spring. One cut per year. That's it.

Verbena bonariensis

Tall, wiry stems topped with clusters of tiny purple flowers that float above everything else in the border from midsummer to first frost. Verbena bonariensis reaches 150cm or more but its stems are so slender and open that you can see through them — it adds height without blocking the view or creating a solid wall. This makes it perfect for weaving through other plants rather than standing behind them. Butterflies and bees love it. It self-seeds freely, which means once you've planted it, you'll have it forever — appearing in slightly different spots each year, which keeps the border feeling natural and unforced.

Evergreen shrubs for permanent structure

Tall grasses and perennials provide seasonal drama, but they disappear in winter. That's why the back of a border needs at least one or two evergreen anchors — plants that hold their form and foliage when everything else has died back. Shaped evergreen cones or pyramids work brilliantly here, giving strong vertical structure year-round. Portuguese laurel can be grown as a loose shrub or trimmed into a more formal shape. Photinia 'Red Robin' adds a burst of bright red new growth in spring against dark evergreen foliage. Elaeagnus is tough, fast-growing, and stays dense and clothed right to the ground.

Buddleia

The butterfly bush earns its common name — plant one at the back of a sunny border and you'll have butterflies visiting all summer. Buddleia grows fast, reaching 200cm or more, with long panicles of purple, white, or pink flowers from July to September. It needs hard pruning each spring (cut back to about 60cm) to keep it from getting leggy and top-heavy. If you skip the pruning it gets enormous and bare at the base, which defeats the purpose. But if you're willing to give it that one annual cut, it rewards you with masses of flowers and a constant stream of wildlife all season.

Calamagrostis 'Karl Foerster'

A tall, narrow, upright grass that reaches about 150cm but stays only 60cm wide. That slim profile makes it perfect for borders where you need height without bulk. The stiff, vertical flower stems emerge in early summer and turn a warm buff colour by autumn, standing all through winter. Plant a line of three or five and they create a clean, architectural screen that works equally well in a contemporary scheme or a more traditional cottage border. Like miscanthus, one cut in late February is the full annual maintenance.

Frequently Asked Questions

How tall should plants be at the back of a border?

Aim for 100–200cm depending on the overall depth of your border and what you're trying to screen. For a 1-metre deep border, plants at 100–120cm create enough height without overwhelming the space. For a deeper border of 150cm or more, you can go taller — 150–200cm — without losing proportion. The back layer should be taller than the middle layer but shouldn't dwarf everything in front of it.

What is the best low maintenance plant for the back of a border?

Miscanthus and calamagrostis are the lowest maintenance tall border plants — both need just one cut per year in late February. For an evergreen option that needs minimal attention, a shaped evergreen cone or a Portuguese laurel needs one or two trims annually. All of these will hold the back of your border with almost no ongoing effort.

Should the back of a border include evergreens?

Ideally, yes. Tall perennials and grasses provide height and drama from spring to autumn, but they die back in winter. Without at least one or two evergreen plants at intervals along the back of the border, you're left looking at bare stems and a fully exposed fence for five months of the year. Alternating evergreen structure plants with seasonal performers gives you a backdrop that works in every season.

Every one of our Border by the Metre bundles includes a structural evergreen anchor at the back layer — so your border has year-round presence from day one. Delivered free to your door.