AFTER the sunniest spring on record, and a long dry period, soft rain has triggered a delicious earthy smell that lingers in the air. Scientists have dubbed this odour petrichor, and attribute it to a combination of the oils released by plants in dry weather and chemicals produced by bacteria in the soil.
It feels as if the garden, too, can breathe again. Some plants that wilted or sulked during the drought have perked up quickly, taking up where they left off their annual growth a month before. Others have been dried to a crisp. And some, like my Buddleja globosa, never blinked.
This lesser-known cousin of the common butterfly bush is covered in turmeric-coloured spherical flowerheads. How a plant fares in times of drought is mainly due to where it hails from; the buddleja is native to mid Chile, a Mediterranean climate zone that experiences two to three months of drought each year.
Sesbania punicea is also from South America, and in my garden its first clusters of bright orange flowers are about to open. If it is dead-headed, it will deliver these through the hottest English summer.
I was inspired to grow it alongside another graceful lacy-leaved member of the pea family, Caesalpinia gilliesii, by seeing the successful association in a dry garden nursery run by Olivier Filippi in the south of France. In June and July, its soft yellow blooms with whiskery red stamens are a delight. Both deciduous shrubs are only borderline hardy; so they need a sheltered spot. Filippi adds vibrant red-flowered Salvia microphylla “Royal Bumble” and red-hot pokers to the fiery mix.
Hardier and even more drought tolerant are a couple more staples on my sunny plot. Giant fennel has sent up a stem ending in tight fists of hundreds of tiny mustard-yellow flowers that give height to the back of the border. These will set seed over the summer and the filigree foliage at the base die back, leaving just a hollow desiccated spike. This is a plant adapted to the climate of the Mediterranean basin. The delicate leaves appear in autumn, and add a fresh airy presence to the winter garden.
While giant fennel can provide vertical accents, Phlomis russeliana, is a perennial that spreads horizontally in a border by means of rhizomes. From May to September, tall stems bearing whorls of pale-lemon-yellow flowers rise from the rosettes of heart-shaped leaves.
This plant association, as well as advice and interesting asides, is suggested by Tony Hall in his new book Gardening with Drought-Friendly Plants (Kew Gardening, £25 (Church Times Bookshop £22.50); 978-1-84246-709-1). Tony, based at the Royal Botanic Gardens, Kew, has studied, collected, and worked with Mediterranean plants for more than 20 years. It may be a while before we can see such plants in their native lands, but we can still enjoy them in our gardens.