Pelargonium quinquelobatum

Words: John Hoyland

Everything about this plant is appealing.  Even saying its name out loud is something to relish. The downy, apple-green foliage looks fresh as spring even during the summer.  The flowers are small and biscuit-coloured.  When they first appear they don’t look that promising but as the temperature and light-levels rise they develop an iridescent sheen on the petals.

Grow with: scented-leaved pelargoniums such as the silver-leaved P. tomentosum

Good things: Nothing like the blowsy pelargonium hybrids.

Bad things: Pauses from flowering during the heat of high summer.

Cultivation: If you have a warm greenhouse sow the seeds in the autumn, otherwise wait until March

Height and spread: 15cm x 10cm (6in x 4in)

Nicotiana langsdorfii

Words: John Hoyland

A tobacco plant with more elegance than most that forms a neat, compact plant.  The narrow, tubular flowers are pale yellowy-green, the colour of Brimstone butterflies.  It’s a great colour to use near dark purples and blues.

Grow with: the shrubby Salvia lycioides.  The blue flowers of the salvia match the Nicotiana’s pollen.

Good things: Look into the flower and you will see that the pollen is bright blue.

Bad things: To show you can’t have everything, the flowers, unlike other tobacco plants, have no scent.

Cultivation: Seeds germinate very quickly.  Sow in late March and the plants will start flowering in June and still going strong in the autumn.

Height and spread: 75cm x 35 cm (30in x 14in)

Dolichos lab-lab

Words: John Hoyland

Another plant name that is satisfying to say out loud. It’s just a bean, but far more beautiful than any other bean you will ever grow. The flowers are mauve and pale pink and develop beautiful polished-purple pods. It’s the startling colour of the pods that really make this plant stand out.

Grow with: white sweet peas for a startling contrast.

Good things: Will grow in burning sunshine or cool, semi shade.

Bad things: The foliage can be shredded by cold winds so grow it in a sheltered place.

Cultivation: Sow the seeds indoors in the warmth. During the summer, keep the plant well watered.

Height and spread: 180cm x 35cm (6ft x 14in)

Tithonia rotundifolia ‘Torch’

Words: John Hoyland

Tall annuals are miraculous: from sowing the seed to 4ft tall and covered in flowers in a couple of months. This is known as the Mexican sunflower but the flowers are much smaller, about two inches wide at the end of branching stems. An ugly, dwarf Tithonia has been bred that has none of the splendour of ‘Torch’. Make sure you buy this cultivar.

Grow with: the burnt orange flowers and dark foliage of Dahlia ‘David Howard’

Good things: In rich, moist soil it will grow to 6ft, the same height as in its native Mexico.

Bad things: Late to flower. It doesn’t get into its stride until the end of August.

Cultivation: Sow the seed in April or even early May, later sowings soon catch up.

Height and spread: 180cm x 100cm (6ft x 3ft)

Lathyrus sativus var. azureus

Words: John Hoyland

The delight of this plant is advertised in its name: azure blue pea-like flowers. Smaller than those of sweetpeas the flowers are an intense, rarely-found, silvery blue, enhanced by the grey-green foliage. As a climber it is a bit weedy. It looks far better left to scramble over the edge of containers

Grow with: silver-leaved plants such as Convolvulus cneorum or at the base of Astelia chathamica

Good things: It comes true from seed so collect your own.

Bad things: If you don’t cut back the spent flowers it will stop flowering.

Cultivation: Don’t sow in November with sweet peas - wait until March.

Height and spread: 75cm x 35 cm (30in x 14in)

Agrostemma githago ‘Ocean Pearls’

Words: John Hoyland

This is a form of the British native corncockle and will grow anywhere. It is an upright plant that doesn’t take up a lot of space and is covered in flowers from top to toe. The petals are a dazzling white with fine speckled lines at the base.

Grow with: Plant in front of evergreen hedges or against the dark foliage of Physocarpus opulifolius ‘Diabolo’ or, as here, with Delphiniums.

Good things: Floriferous and long-flowering if you remove the dead flowers before they set seed.

Bad things: Weak stems. They need the support of other plants to keep them upright.

Cultivation: Sow them in situ in March and April and remove the whole plant in the autumn to stop its seed from going everywhere.

Height and spread: 75cm x 30 cm (30in x 12in)

Persicaria orientalis

Words: John Hoyland

An imposing plant that will grow as tall as a sunflower (2.5m in my garden) by the middle of August. The shoots are draped with dark cerise tassels, the texture of chenille. The stout main stem resembles bamboo. In America it is known as ‘Kiss me over the garden gate’. I don’t know why that is, but I like the sentiment.

Grow with: large groups of Rudbeckia laciniata ‘Herbestonne’

Good things: It’s big, bold and needs lots of space.

Bad things: It’s big, bold and needs lots of space.

Cultivation: In April you can sow seeds directly into the border where you want the plant to grow.

Height and spread: 2.5m x 1m (8ft x 3ft)

Argemone grandiflora

Words: John Hoyland

A relative of the poppy whose flowers have the same ethereal quality as the field poppy. The individual flowers have gossamer-thin white petals that look like tissue paper. Each flower is about 4 inches wide and in the middle of summer the glaucous foliage is smothered in flowers.

Grow with: the bright red flowers and glaucous foliage of the horned poppy, Glaucium corniculatum

Good things: It will thrive in baking hot situations, conditions that cause most annuals to expire.

Bad things: When the foliage dies it dries to a vicious, prickly mess that feels like thistles.

Cultivation: The seedlings don’t like being moved so sow in situ in mid April.

Height and spread: 60cm x 40cm (2ft x 15in)

Orlaya grandiflora

Words: John Hoyland

This is the flower to grow if you want to evoke the white froth of cow parsley without introducing an invasive plant into the garden. The foliage is fresh, bright green and feathery; the flowers are sparkling white Nottingham lace. There is a ruff of flat petals around the flowerheads that acts as a landing pad for hoverflies and other insects.

Grow with: Perfect amongst airy grasses such as Deschampsia cespitosa.

Good things: It seeds itself about at a very gentle rate, never becoming a nuisance.

Bad things: There is nothing bad about this. It’s a plant that has everything.

Cultivation: You get bushier plants from seed sown in the autumn and over-wintered in a cold frame.

Height and spread: 60cm x 40cm (2ft x 15in)

Rhodochiton atrosanguineum

Words: John Hoyland

Although it is perennial in its native Mexico and in over-heated greenhouses, most gardeners treat this exotic climber as an annual. The flowers are only about 4cm long but by the end of summer the plant is smothered in them.

A rosy-pink bell (the flower’s calyx) sheaths a dark purple tube. When the flower is in bud it resembles a miniature phallus, which always causes much excitement in the Home Counties.

Good things: Floriferous and easy to grow.

Bad things: You have to wait until the end of summer before they start flowering.

Cultivation: If you have a warm greenhouse sow the seeds in the autumn, otherwise wait until March

Height and spread: up to 5m x 50cm (15ft x 18ins) - but in the south of England mine have never got to more than 2m tall

Grow with: Thunbergia alata - the climber Black-eyed Susan which flowers slightly earlier. The rhodochiton will take over when Susan is past her best.

Phacelia tanacetifolia

Words: John Hoyland

For years, like clover and the blue lupin, phacelia was only grown as a green manure: a worthy workhorse of a plant that will improve the soil. Let its buds unfurl and you will have bright powder-blue flowers from June to September.

Bees, ladybirds and, most of all, lacewings love the flowers as much as I do.

Good things: Beautiful and beneficial

Bad things: You need to grow lots to make an impact

Cultivation: Sow directly onto clean soil in March and April. You will have flowers about twelve weeks later.

Height and spread: 75cm x 30cm (30ins x 12ins)

Grow with: other meadow plants. If you want a bit of zing in the garden try it with the gold and yellow flowers of C. ‘Mardi Gras’. Not a combination for the faint hearted.

Nemophila menziesii ‘Baby Blue Eyes’

Words: John Hoyland

Don’t let the big and imposing annuals turn you away from the small and dainty ones. This is a wonderful little plant: only six inches tall but smothered with pale blue flowers. Use it around shrubs, around the edges of tubs or in swathes amongst perennials. It will finish flowering by the end of August so it’s a perfect companion for late-flowering perennials. Always plant lots of them together.

Grow with: a froth of nemesias, diascias and other delicate-flowered tender perennials

Good things: Masses of pale-blue flowers.

Bad things: A single plant looks miserable.

Cultivation: Grows best in partial shade. Doesn’t like to dry out when it’s in flower.

Nicotiana mutabilis

Words: John Hoyland

Sometimes you need to live with plants to appreciate them. This has white flowers that age to dark pink, so you get different-coloured flowers at the same time. I thought this made it look messy when I first saw it, but later, four feet tall in the autumn and still flowering amongst asters and salvias I realised what a great plant it is.

Grow with: Plant so that it grows up through the clouds of tiny flowers of Aster lateriflorus.

Good things: Long flowering. Becomes a large, bushy plant that is covered in flowers.

Bad things: Needs staking or grow it in amongst stronger plants that will support it.

Cultivation: Sow indoors or under glass in the warmth in March or April.

Height and Spread: 120cm x 100cm (4ft x 3ft)

Amberboa muricata

Words: John Hoyland

An airy plant with wispy lilac-pink flowers and petals that look like silk threads. It’s got the same wild look of cornflowers and is best in loose, informal plantings. You need lots of plants, sown in drifts to make an impact. It grows to nearly three feet tall but stands up by itself.

Grow with: Ammi majus, cornflowers, scabious and other wild-looking plants.

Good things: Will grow in poor soil, dry soil in sun or partial shade

Bad things: Unless you pinch it back regularly when young, it will become an unsightly, scraggy plant topped with just one flower.

Cultivation: Sown outdoors in April, it will start flowering in July and carry on until the first frosts.

Height and Spread: 100cm x 35cm (3ft x 13in)

Nigella ‘African Bride’

Words: John Hoyland

This form of ‘love-in-a-mist’ with white flowers that have a chocolate-coloured centre is so easy to grow, and so quick to flower, that it is a good way to get children started with plant growing.

Grow with: everything, everywhere

Good things: Easy to grow; gorgeous flowers; great seedheads

Bad things: Will seed itself everywhere. And that means everywhere: amongst other plants, in pots, in paving cracks. If you don’t want them they are easy to hoe off in spring.

Cultivation: Clear the soil of weeds and sow in situ. Thin out seedlings so that the plants do not crowd each other out.

Height and Spread: 60cm x 40cm (2ft x 15in)

Gilia capitata

Words: John Hoyland

Lavender-blue spheres the size of a golf ball that resemble miniature alliums. Starts flowering in the spring and carries on for most of the summer. It grows best in poor soil in full sun

Grow with: one of the cream-flowered Californian poppies, Eschscholzia caespitosa

Good things: Bees, butterflies and pollinating insects love it.

Bad things: To get it into flower early sow seed the previous autumn and mollycoddle them though the winter

Height and Spread: 40cm x 30cm (15in x 12in)

Delphinium requienii

Words: John Hoyland

A cheat – this is a biennial but if you sow the seeds early it will behave as an annual. It forms columns of ghostly blue grey flowers in early summer. The large, shiny palmate leaves always look fresh and healthy and add a sparkle to the borders before the flowers take over.

Grow with: the vivid, bright orange flowers of Leonotis leonorus

Good things: It is nowhere near as temperamental and difficult as delphinium hybrids.

Bad things: It seeds itself everywhere. Be ruthless on weeding out plants that you don’t want.

Height and Spread: 80cm x 50cm (30in x 19in)