Purple patch: Balance a late-summer garden with a splash of burgundy

The Bishop of Llandaff has got himself something of a reputation lately. Frankly, he puts it about a bit. And everybody loves the Bishop. In the late summer afternoon during the last week of August and first of September, flame colours dominate the garden, and the Bishop's episcopal red flower booms out.

But the Bishop is not just loved for his flowers: dark purple-bronze foliage also does its bit to make the ladies fawn over this glamorously gaudy dahlia, top-rated since it was first bred in the 1920s. Its wine-coloured leaves balance out the bright colours of the late-summer garden beautifully. Somehow that deep burgundy shadow gives hot exotic oranges and limes a fantastic backdrop to show off against.

There are other purple-toned plants that do similarly good work. Sedums are fantastic early autumn plants, and "Purple Emperor" adds a rich red seaweedy colour as a foil to raspberry-coloured flowers. Sedums are delightfully unfussy to grow and will manage well without too much feeding and watering – in fact, they're more likely to do a spectacular belly flop if you do too much. Crocus offers a substantial plant for £6.99 (crocus.co.uk).

Another elegant purple-leafed beauty is Actaea simplex, which comes with the oh-so-tempting common name "Bugbane". Ignore that nomenclature, and you are buying a racy centre-of-attention for late autumn, with almost-black foliage below tall, white-starred flower stems. Actaea will even, usefully, tolerate damp shade.

There are acres of wine-coloured daylilies for gardeners to sort through, but RHS Wisley has done the job for us and selected in particular "Little Grapette", with dark burgundy flowers and orange detailing. The Duchy of Cornwall nursery has it for £.5.50 (duchyofcornwallnursery.co.uk). Lower down in height, there is oregano "Rosenkuppel", a purple confection that grows to a foot or so.

One of the tallest of the burgundys is the dark Korean Angelica, Angelica gigas (£6.99, crocus.co.uk). This is a wine-dark bee-haven, a 9ft stunner with turreted cow-parsley looks, reimagined in pinot noir colours. Gigas does best in really fertile soil with a bit of care and attention – it's worth it, to produce those towering flower stems the second year in your care.

Finally, there are those old favourites, burgundy-leaved canna lilies. I have a soft spot for cannas because I find them just so unbelievably easy to grow. Some have now even seeded themselves in my garden, which I find startling, because their seeds are bullet-like. Canna purpurea is the dark-leaved variety, and some good-named plants include "Russian Red" – £6.50 from British specialists Hart Cannas (hart canna.co.uk). To see them in person, why not drop into Hart Cannas' open day, in Farnborough, Hampshire, today and tomorrow. Admission is £3 – and includes a free cream tea.

Bargains and Bishops

Racy number

Actaea simplex Atropurpurea: a long-winded name for a simply stunning plant. This bargain Bugbane is on offer for £7.99, and just about to begin flowering for autumn. crocus.co.uk

Easy living

Even if you've never grown a Bishop of Llandaff dahlia, it's as easy to get growing as it is sophisticated in looks (£7.50, burncoose.co.uk). Or if the Bishop gets around too much for your liking, how about the "Dark Desire"? £4.50, westcountrylupins.co.uk

High hopes

If you like Angelica gigas, try Peucedanum verticillare. It has the same stunning height and good looks, pinky-purple stems, and lime-green flowers. £6.99 for a two-litre plant, crocus.co.uk