Top the surface with grit, keep an eye out for the red lily beetle (knock it off and crush it underfoot if you spot one) and, come July, tall stems of large perfumed flowers will appear.
You won’t be disappointed, especially if you choose sublime, classic beauties such as snow-white Casa Blanca, freckled rich pink Star Gazer or yellow trumpet-flowered Golden Splendour.
Bag a few bulbs of Lilium speciosum var. rubrum, with speckled pink petals that are curved back like tiger lilies, and you can continue the sensational display through August, too.
BEGIN WITH BEGONIAS
It is hard to believe that the small, rounded tubers of begonias can produce, in a matter of weeks, possibly summer’s most prolific container displays that will keep high-kicking for months.
Just coax them into action now in pots of moist compost and, when the tubers start to sprout sturdy leaves, plant them into pots, hanging baskets and window boxes, where the flowers can, and will, cascade.
If begonia’s typically big and blowsy blooms are too full-on for you, try a subtler species, such as bertinii, which will produce literally hundreds of hanging four-petalled scarlet flowers from just one tuber.
Now that breeders are producing gladioli in sumptuous shades of velvety deep reds through to violet, these flamboyant flowers are in high demand, especially for a cutting patch. Plum Tart, a deep magenta, is currently the garden designers’ gladioli of choice, and looks sensational among the acid green of euphorbia.
Dare to wave a gladdy or three this summer by planting the corms three-to-four inches deep in a sunny spot, next month, and keep planting every few weeks through summer for a succession of stand-out, stand-up flower spikes.
Dahlias are peerless in injecting pizzazz by the bucketful to the late summer lacklustre border or for revving up a jaded container display.
Raise them in much the same way as begonias, by settling each tuber, which looks like an ugly cluster of roots, into its own large plastic pot of multi-purpose compost. Keep it moist, either in a greenhouse or on a sunny windowsill, and the dead-looking woody stump at soil-level will soon start to shoot.
The choice is dazzling, from enormous dinner plate dahlias, such as luscious pale peach Café au Lait to small, neat pompom varieties, such as burgundy Dark Spirit. Some, like peony-flowered, cream Classic Swan Lake, or the scarlet Bishop of Llandaff, have the bonus of dark bronze and chocolate foliage.
PINEAPPLE AND PEPPERMINT
At about the same time as the dahlia, the pineapple plant puts in an appearance, displaying its spectacular two- to three-foot spikes studded with starry flowers and topped with a pineapple-style tuft, to be followed by equally dramatic seed heads.
If you want a curiosity among your containers, Eucomis is the easy-to-grow bulb for you. Eucomis bicolor is palest peppermint green, while Sparkling Burgundy has deep-pink flowers crowding burgundy stems and strappy leaves.
Nerines delight in September and bloom until November. The trick is to plant the bulbs just below ground level, in a sunny, well-drained spot, ideally against a south-facing wall. Little effort, big dividends.