Cosmos is the annual summer flower that will produce a constant supply of large, daisy-like blooms on tall stems amid clouds of ferny foliage. It looks wonderful in the border and equally good in a vase. Cosmos is easy to grow from seed, has a colour range from clear white and pink to plum, and you can find it now, ready to plant out, at garden centres.
Cut-flower queen Sarah Raven reckons that cosmos produce two buckets of cut blooms a week from a metre-square patch, from late June until November, which equals 50 buckets of flowers. If you grow just one flower for cutting, this is the one.
Salvia Caradonna is the high-performance perennial at the top of many garden designers' planting lists. All of the Salvia nemerosa group are worth growing for their mass of purple flowers but Caradonna is the finest, with compact, near-violet flower spikes that make a great foil for roses and are adored by bees and butterflies. Give drought-tolerant Caradonna a sunny spot and it will reward you with blooms until October. Admire it at the outstanding Old English Garden, designed by Sarah Price, in Battersea Park.
Another hit with designers — and with those who like a sharp hit of intense colour in their borders — is delectable Prinses Juliana, a Geum with hot orange, ruffled flowers on wiry stems that makes a striking highlight among deep, dark perennials or evergreens. Geum Mrs J Bradshaw, with pure scarlet flowers, is another summerlong winner.
Deadhead penstemons and you can expect flowers from June to November, then prune them hard after frosts to ensure a repeat performance next summer. Another reason to grow these hard-working perennials is that they are resistant to slugs. Old variety Alice Hindley, which holds the RHS Award of Garden Merit, has the prettiest white-throated lilac bell flowers on tall, 90cm stems that need no staking.
Why buy a rose called Lucky when you can have one called Madame Isaac Pereire or Ferdinand Pichard? Because although many of the old French varieties are beautiful and worthy roses, Lucky is the outright winner in the longflowering stakes. I can confidently report that I have seen it, in a friend's garden, outperform every other rose in town. The flowers aren't as beautiful as the fuller French roses, but they are pretty, they are robust, they make great cut flowers because the stems are sturdy, and the blooms don't collapse at the first trickle of rain.
Lucky was Rose of the Year five years ago, and Rose of the Year 2015 at last week's Hampton Court Flower Show, For Your Eyes Only, is glorious: apricotpink, fluttery flowers with a plumsplotched centre and golden stamens, a delicious scent, good disease resistance and the promise of flowers all summer long. After all, Warm Welcome, a rich orange patio rose from the same stable, Warner Roses, has been known to produce blooms until Christmas. Place your orders now.