Sowing sunflowers is child's play: just push the seeds into the ground, then watch and wonder as they reach dizzy heights. Grow spectacular new Shock-o-lat from Suttons this year - it delivers fiery reddish-bronze flowerheads with yellow-tipped petals and chocolate brown centres, on two metre-high purple stems.
If you want them for cutting, grow them closer than normal - 25cm apart - for smaller blooms, but more of them. However, if you prefer your flowers daintier, a new flax is tinted not the usual blue, but the prettiest apricot-pink, with deeper strawberry jam-shaded centres and ferny foliage; Linum Charmer Salmon, again from Suttons, could be just the job for summer containers.
Pedigree plant: Cottage-garden larkspur goes glamorous with Consolida Avatar
Californian poppies are renowned for their prolific, silky flowers that only open in sunshine, but vermilion variety Red Chief, trialled by Thompson & Morgan over two years in our unreliable climate, has proved to flower well, whatever the weather.
Nasturtiums are often used to round out a hanging basket. Just push in one fat seed wherever you need an infill of colour. However, T&M's new Firebird nasturtium, with velvety red and golden blooms, is a high-performing solo flyer, and promises to create a cascade of colour from hanging basket, windowbox or container.
New Larkspur Consolida Avatar, from Suttons, is as extraordinary as its pedigree title. Like a dainty delphinium, and from the same family, this glorious, rich blue and purple flower can be rocking your garden this September, provided you sow it under glass by March.
Flower arrangers, look no further than Amaranthus tricolor Red Army from Sarah Raven. It produces sensational long, crimson tassels on similarly shaded stems. It's gorgeous trailing over the side of tall vases.
Sweet peas are essential for endless jugs of fragrant flowers through summer. T&M's Robert Uvedale, a stunner with large, frilly, shocking pink blooms, is named after the Enfield teacher credited with bringing the sweet pea to England in 1699.
The sweetest pea: Robert Uvedale has large, shocking pink blooms
Resolve to grow edibles that look as good as they taste, such as Marshalls' new pinky-violet Ruby Crunch sprouts, or - you could mix them together - Rubine, from Sarah Raven, a sumptuous purple-streaked green to sow in March for impress-the-guests supper parties come October.
Climbing beans can be hit-and-miss, but T&M's new high-yielding Monte Cristo have fleshy, bright green pods, roughly 25cm long, that remain crisp and stringless, even if you can't harvest them for a few days.
The search is always on for the finest cherry tomato, with that perfect balance of sweetness and acidity, and T&M claim to have found two that excel in taste tests - scarlet Sweet Aperitif and the dusky, rose pink beauty Rosella.
Chilli peppers are increasingly popular and British-bred Pot Black, with its mass of glossy, mahogany-coloured fruits, again from T&M, is a must for patio pots and window boxes.
Finally, it might not be new - Italians have been growing Tromboncino forever - but it might be new to you, and hasn't yet reached the UK supermarket shelves.
As decorative as they are delicious, the numerous yellow blooms and trombone-shaped fruits look wonderful hanging from an arch, and couldn't be easier to grow. Fritter the flowers, eat the fruits small as a courgette, or cut when larger and keep as a winter-storing squash. No veg is more versatile.
- Suttons: 0844 922 0606 (suttons.co.uk)
- Thompson & Morgan: 0844 573 1818 (thompsonmorgan.com)
- Sarah Raven: 0845 092 0283 (sarahraven.com)
- Gardening problems? Email our RHS expert at: firstname.lastname@example.org