Annuals are a cheap and easy source of glorious summer colour. Louise Midgley picks her top 10 to sow now, outdoors or undercover
Annuals are the most accommodating of plants, completing their life cycle within a year and hard-wired to flower prolifically in order to produce an abundance of seed and perpetuate their species.
A select few, taller than average varieties, have great presence in the garden and make striking stand-alone plants both in the border or in their own container. Grown in drifts or blocks of single or mixed colours, these statement annuals will provide a dramatic, long-lived display and a ready supply of cut flowers for the home.
Often hard to find in garden centres or online, most are easy to grow from seed, either sown in situ or started off in the greenhouse. Seed bought this year will last until next if stored correctly, so don’t be tempted to sow the whole packet in one go if it contains more than you need. All these lovely plnats have in common a need for a sunny position or light shade and free-draining soil.
1. Nicotiana sylvestris An elegant, flowering tobacco plant, destined to steal the limelight. Its bold architectural form would grace a traditional cottage garden as much as any modern design. A majestic tower of highly scented, white trumpet-shaped blooms emerges above plate-sized aromatic leaves. In order to attract pollinating moths, the flowers’ fragrance becomes more pronounced at dusk, so position plants somewhere they’ll be appreciated. Although officially a short-lived perennial, Nicotiana sylvestris is better treated as an annual in colder climates. H1.5m (5ft) S60cm (2ft)
2. Nicotiana mutabilis ‘Marshmallow’ One of the more unusual tobacco plants, which displays a wonderful array of tri-coloured flowers simultaneously. This exquisite variety produces its long, dainty stems in an open, light and airy formation. All are adorned with small blooms that range in colour from deep magenta to pale pink and white. The graceful movement of the almost weightless wands of flowers, as they catch the breeze, is compelling to watch. For this reason, it combines well with other plants that add a touch of lightness to the border, such as grasses and Gaura lindheimeri. H1.2m (4ft) S60cm (2ft)
3. Cleome hassleriana Also known as the spider flower plant, thanks its extraordinarily long stamens that protrude from orb-shaped blooms. The exotic-looking flowers in tones of pink, lavender, white and purple rise to the top of strong, thorny stems like giant sparklers erupting and need little support despite their lofty dimensions. A position in full sun will intensify their spicy fragrance, especially in the evening, and will prolong flowering until the first frosts. Happy in an average garden soil and fairly drought tolerant once established. H90-120cm (3-4ft) S30-60cm (1-2ft)
4. Ricinus communis ‘Impala’ Create a tropical vibe in your garden with towering castor oil plants. These fast-growing annuals develop sizeable, palmately lobed leaves in hues of purplish bronze and spikes of small yellowish flowers followed by unusual spiky, scarlet seedpods. It’s grown as a shrub in tropical regions where it reaches in excess of 8m (26ft) but ‘Impala’ is more compact and makes an attractive feature annual when grown at the back of a border or as a centrepiece in an island bed. All parts of the plant are poisonous. H1.5m (5ft) S1m (39in)
5. Tithonia rotundifolia Mexican sunflowers are invaluable annuals for injecting late summer colour and a strong vertical dimension into a planting scheme. Branching stems, which may need staking, bear vivid tangerine-coloured flowers, reminiscent of single-flowered dahlias or pot marigolds. The fact they hail from South America tells us this plant needs plenty of heat to give of its best. Partner with other lofty, late-summer flowering plants such as salvias, penstemons and Verbena bonariensis for a vibrant, jewel box of colour. H1.5-2m (5ft-6ft 6in) S30-60cm (1ft-2ft)
6. Helianthus ‘Harlequin’ F1 Hybrid As an alternative to traditional single-flowered sunflowers, multi-branching varieties provide a more floriferous display with their abundance of happy, daisy-shaped flowers in sunny hues. Harlequin sunflowers produce 15cm (6in) bi-coloured blooms in warm shades of bronze, rose pink, burnt orange and gold. Position them at the back of the border and give them enough space to spread their wings. They associate well with other architecturally striking annuals or perennials. H1.5m (5ft) S50cm (20in)
7. Papaver somniferum Grow opium poppies not just for their attractive single or double flowers but also their ornamental seed pods. These orb-shaped receptacles contain hundreds of seeds that will disperse around the garden and provide a constant source of new plants in future years. Seedlings may not always spring up where needed but are easily recognisable and can be removed. The flowers are predominantly but not exclusively in the pink, purple and red spectrum of shades and all have appealing silvery glaucous foliage. H60-90cm (2-3ft) S30cm (12in)
8. Ammi majus ‘Graceland’ This elegant umbellifer creates a froth of white lacy flowers above weightless ferny foliage. Bees and butterflies are magnetised to the open blooms and birds are later attracted to the seed heads. Weave the plants among other border specimens for support or plant in groups staked with natural looking twiggy stems. Graceland blooms from June to August but can be extended with successional sowings. Its cut flowers have a lengthy vase life and combine beautifully with any other flowers in season. H140cm (55in) S50cm (20in)
9. Nicandra physalodes A vigorous and striking annual that owes its common name shoo-fly to the fact some gardeners believe it repels white fly. For this reason, it’s often seen growing close to brassicas in allotments. Lilac/blue funnel shaped flowers with white throats open daily on wide spreading, self-supporting plants. The purple calyces that surround each flower expands after flowering to encase the seeds in rigid papery globes, much like the orange Chinese lantern plants (Physalis alkekengi) making it a great garden worthy plant. H1.2m (4ft) S1m (39in)
10. Cosmos ‘Sensation’ A traditional, stalwart of the ever-expanding cosmos family that reliably produces a mass of long-stemmed, daisy-shaped flowers from early summer until stopped in its tracks by the frost. Give these tall accent plants a strong support from the start as the weight of filigree foliage and blooms on a mature plant can cause the central stem to buckle. Sensation can be found in mixed hues of pink, magenta and white. H120cm (4ft) S60cm (2ft)