We may be only days away from the Autumn Equinox but my garden is riding high on a late heat-wave.

Lobelia as blue as the sky is all aflutter with tortoiseshell and small white butterflies while the sky itself is alive with swallows testing out their wings and carving great arabesques above me.

Bees bumble in and out of the pollen rich centres of cosmos which is bobbing in the breeze. The roses have got their second wind and the dahlias are smouldering in the border but it is the cosmos that holds sway.

Great swathes of carmine red light up the borders with, here and there, plants with paler pink petals.

They are all ’Dazzler’ but as I have grown them from a packet of seeds there are variations not only in colour but in the size of the flowers for some are as big as my fist and some would neatly fit into the fist of an infant.

Cosmos bipinnatus is easy to grow from seed and almost as quick to germinate as mustard and cress.

I started them off in the greenhouse but in years past I have sown them in trays on the kitchen windowsill. This year I gave away as many as I kept and still had enough to fill the borders and several big pots beside the back door.

You can sow indoors from February to April and if you, like me, sometimes let the time slip by you can buy young plants by the half dozen although they are almost invariably a mixture of red, pink or white single flowers.

Grow from seed and the choice widens to include the primrose yellow ‘Xanthus’ and ‘Candy Stripe’ a white with a red picotee edge.

‘Fizzy Purple’ lives up to its name being deep purple with a positive ‘fizz’ of narrow petals at its centre for the breeders have been busier than bees producing ever more complicated flowers. The ‘Double Click’ series are doubles with flouncy petals whereas ‘Seashells’ bears fluted petals and ‘Cupcake’ is the most extraordinary for the petals are fused together.

Personally I prefer the simple ‘Dazzler’ and next year intend to grow an old favourite ‘Purity’ whose white daisy flowers are back of the border beauties.

If you like Xanthus then look out for seeds of Cosmos sulphureus with deeper yellow or orange flowers and selections like ‘Diablo’ in day-glow orange or ‘Bright Lights’ canary yellow edged in orange.

These are all annuals but Cosmos astrosanguineus is a tender perennial and like all the other cosmos is a native of Mexico and Arizona just over the border.

You know it as the chocolate cosmos because it really does smell of chocolate and besides which it is a very deep maroon verging on black and so the very richest chocolate with a scent to match.

You will find plants in garden centres and catalogues, Thompson & Morgan sell it as ‘Chocamocha’. Like the dahlia this cosmos produces tubers and can be over-wintered to spring into life next year.