While many people focus on garden perennials, we should not forget that there are a host of gorgeous annuals out there too. Annual climbers are too often overlooked and yet can bring subtle touches and welcome bursts of colour to brighten the garden in summer. Often from tropical climates, the brightly coloured flowers can be transporting. Annual climbers can also be handy to disguise and soften surfaces, which can help to change the feel of a particular part of the garden. Speed of growth also makes annual climbers ideal for clothing a new garden, providing temporary and flexible screening or softening hard surfaces. Here are some of the best types of annual climbers.
Thunbergia alata ‘African Sunset’
An attractive selection, displaying masses of dusky brick-red to soft-cream flowers with a black centre backed by triangular mid-green leaves. This annual climber comes in a range of colours, from pale yellow to pinks but the dark centre of the flower is always an identifier. The climber is easy to look after, doesn’t require pruning although you should watch out for aphids and powdery mildew. For sun or part shade. Height 2.4m. USDA 9a-10b
Lathyrus sativus f. azureus
An annual climber in the shape of an elegant, fragile and dainty sweet pea. With grassy foliage and small, beautiful, azure-blue flowers, belies a tough constitution. It is an annual that’s tiny and bright blue and doesn’t have a strong smell and as it’s so tiny, would work well planted near a path or patio. It is tolerant of drought and waterlogging. 90cm. USDA 1a-11.
Also called Mexican viper, and mentioned in one of Charles Darwin’s books, The Movements and Habits of Climbing Plants, this annual climber is a pretty, free-flowering herbaceous climber that supports itself with the aid of twining leaf stems. Worth growing for its ivy-shaped leaves and elegant, foxglove-like flowers. And blooms stick around through summer and into Autumn. It also is generally pest and disease free. Make sure there’s full sun as the climber thrives in light, well-drained soil. 1.5m.
Ipomoea purpurea ‘Star of Yalta’
This herbaceous perennial, grown as an annual, has deep-purple, almost velvet-like flowers with a star of deep pink radiating from the centre of the flower to the tips of the petals. Native to South America, it has rich green foliage in summer and is easy to raise from seed. The annual climber can also be used as ground cover as well as on walls and fences, in a greenhouse or conservatory. Plant in a sheltered spot in chalky, loamy or sandy soil. 1.8m.
This fast-growing tropical annual climber produces exotically shaped flowers of vivid deep blue. It has many common names including butterfly pea and Darwin pea. In India, it is used in puja rituals as a holy flower. It needs plenty of warmth and sunshine and is at its best during long, hot summers. 2.4m. USDA 10a-11.
The large, greenish-white flowers of this outstanding species turn dark purple as they age. It flowers best on moist, well-drained soil. 5m. RHS H2, USDA 9a-11.
Makes up for its lack of fragrance with striking deep rose-purple flowers and a vigorous disposition. Drought tolerant, it likes a warm position in full sun. 1.5m.
Lablab purpureus ‘Ruby Moon’
The richly coloured purple blooms and shining purple pods that follow are complemented by purple-tinted foliage. It boasts a spread equal to height depending on the growing conditions. 6m. USDA 7a-10b.
Lathyrus odoratus ‘Cupani’
Glorious sweet pea popular for its sweet fragrance and regal magenta and purple flowers, which are freely produced. Pick regularly to prolong the display, which often lasts until first frosts. 3m. RHS H2.
Often commented upon for its profusion of distinctive, and somewhat vulgar, tubular, black to reddish-purple flowers. Also has dark stems and heart-shaped, rich-green leaves. 3m. USDA 10a-11. RHS H2.
Ipomoea purpurea ‘Grandpa Ott’
Similar in vigour and appearance to ‘Star of Yalta’ but with a rosy, rather than white throat. Requires a warm, sheltered position to grow. Flowering continues into early autumn. 3m.
Handsome native of South America, valued for its attractive, bright-red flowers and deep green, fern-like foliage. It is drought tolerant and a favourite of humming birds. There is also a white form. 7m. USDA 11-12.
Ipomoea lobata ‘Jungle Queen’
The vibrant, multi-coloured tubular flower-spikes of this particularly robust selection (from K Sahin’s in the Netherlands) display a greater colour contrast than the species. For sun or shade. 3m.
An open, slender climber that produces tubular flowers in shades of red, orange, pink and yellow, from late spring to autumn. The leaves, formed of greyish-green leaflets, create a pleasing texture. 3m. RHS H3, USDA 8a-11.
Phaseolus coccineus ‘Painted Lady’
Runner beans have long been grown as ornamentals for gazebos and arbours. This pre-1855 cultivar produces tasty, medium-sized pods and the attractive flowers can also be used as a garnish. 3m.
The contrasting colour combination of brick-red and yellow makes this a pleasing yet unusual plant that is well worth seeking out. It is excellent trailing in containers or as a compact climber. 1.2m.
A fascinating climber from Argentina and Chile with unusual, star-shaped, downward-facing, apricot flowers, twining stems and stinging hairs (only on mature plants). Also known as the twining tingle lily. 3m.
Bright yellow-green and lime flowers ensure that this cheerful native of Asia Minor, will never go unnoticed. Best plants come from autumn sowings. Ideal for scrambling over a hedge or up twiggy supports. 1.8m or more.
There are many forms of this cheerful plant with fresh-green leaves and brightly coloured flowers in shades of red, yellow and orange. Happy to assert its right to roam wherever the gardener allows. 3m. USDA 10a-11
Cucurbita maxima ‘Turk’s Turban’
These must-have winter squashes can be trained over arches or pergolas to add a sense of playfulness to a garden with their surreal shapes and colours. They are also an invaluable plant for late-season interest. 2m.
Given a warm, sheltered position this Ipomoea offers delicate white, sweetly fragrant, flowers up to 15cm in diameter. These open in the evening and disappear around dawn. 3m. USDA 10a-12.
Words by Matthew Biggs, Kew-trained plant experts and BBC Radio 4 Gardeners’ Question Time regular.
Hardiness ratings given where available.