Summer time blues: Autumn may be just around the corner, but your garden can keep right on blooming

Maybe I'm in denial about the basic reality of nature, but I can't stand the idea that we should already accept a general turn towards autumn. OK, I concede that there are berries and fruits growing where earlier there were blossoms. But if we're lucky enough to have another warm autumn, the garden could be flowering for months more. I don't want to give up the fight just yet.

Of course days will slowly grow shorter. But somehow those warm days of late August and September often have a sense of possibility rather than loss. In particular there are fine plants only just coming into their own in the garden.

There's the deservedly well-loved Salvia guaranitica, for a start. This stunning sage comes in the most vivid lapis-lazuli blue, straight out of a medieval book of hours. It will carry its flowers for at least the next couple of months, given the right spot: it needs as much sunlight as possible to encourage flowering. It's not reliably hardy, so by the house or a wall is best; but in the right spot it can become a great explosion of blue at the back of a border, delighting your eye every time you go outside.

For summer longevity I also swear by the gingers and canna lilies. You may not be a big fan of the tropical look, but a clump of ginger will have a saucy, jaunty effect, without you needing to become a complete convert. Set aside those gaudy flowers and you still have the leaves – the inspiration for countless engineers with their beautiful strong structures lit up by the sun shining through them. The leaves will continue to come till windy November checks their growth, and will finally die down with the first frosts (this year, in my garden, that wasn't until February).

I have also this year replaced two oleanders that bit the dust a while back. A holiday in France last summer reminded me how great these plants are for continuous flowering, adding a permanent exotic touch to a London back garden.

Mine are cream and dark rosy pink, and will keep flowering as long as the weather is vaguely warm. I love their leathery leaves and ability to manage for a week without being watered, too. Again, they are not particularly hardy, so plant near to the house in a hot spot. And for the holiday spirit, choose one with a scent that will float across the evening garden: imagine yourself in Madrid, Los Angeles, Athens – anywhere but here.

So there are my recommendations to keep autumn at bay. Though this is not to say I will be missing out on any blackberry picking. I'm not totally stupid.

This bud's for you: More late developers

Hedychium

Buy this in leaf, not as a rhizome, or you could be waiting a long, long time. Hedychium greenii, a fairly hardy species with bright orange flowers, is on offer from Crocus.co.uk at £6.95. Junglegardens.co.uk has the amazing pink "Elizabeth", for just £7.88.

'Salvia guaranitica'

Salvia guaranitica Black and Blue has an inky blue calyx, adding to its dramatic appearance. Try Roseland House Garden & Nursery (01872 560451, www.roselandhouse.co.uk).

'Nerium oleander'

For pure white Nerium oleander, the cleanest of looks, go to Burncoose.co.uk – £11 a plant. But for the widest choice of colours, go to French nursery Pépinère Filippi at www.jardin-sec.com