Discover some unsung heroes that can pack a punch

CARL LINNEAUS, the famous Swedish Botanist, sometimes referred to as the father of taxonomy, created a bit of a storm, when in 1753 he created the classification of Geraniaceae. He put the hardy North American geraniums, which we know as cranesbills in with the tender South African pelargonium, which we also call geranium. Cranesbills are universally used in our herbaceous displays, and most people use the non-scented brightly coloured tender geraniums, but there are more, wonderful geraniums which should be considered – the scented leaved geranium.

These geraniums (pelargonium) have approximately 800 species, which originate mainly from the warmer regions of South Africa, which is why these amazingly versatile plants are sadly frost tender. Don’t be put off. Their attraction is their scintillating leaf scents; aromas of lemon, rose, orange and peppermint are some of the delicious varieties on offer. The scented oils, which are emitted when brushed against, are found in hairy oil glands on the leaves. Much prized by herbalists and aromatherapists for their soothing and antibacterial qualities, it is no surprise that the pharmaceutical industry uses the oil from Pelargonium 'Graveolens' in many cosmetics, soaps and perfumes.

At RHS Garden Harlow Carr we use them in our summer containers; they are my unsung heroes, as they are very subtle, but pack a real punch when discovered. We use John Innes No 2 and a multipurpose compost to keep them happy throughout the growing season, and plant them out in late May. In the Scented Garden there are a medley of plants to enjoy this year – the most pungent of my choices is Mabel Grey; she has the most delicious sherbet-lemon scent, with pale pink delicate flowers. She is tucked in with the eye-catching, variegated cream and green of Lady Plymouth, descended from one of the original ‘Graveolens’ brought to the UK on one of the trading vessels in the 18th Century. Her old fashioned musky rose scent is not as strong as some of the others on offer, but she is very showy and her trailing habit attractively cascades down the sides of the pots and containers all summer. There is also Ashby with dark green, deeply incised leaves, with rich purple flowers and a delicate rosy scent, mingling happily with all her bedfellows.

Our Kitchen Garden team has used these delightful beauties in their containers this year too. They have chosen the well-known Attar of Roses, one of the most vigorous of all the geraniums, another rose scent, with handsome light green hairy leaves, and an abundance of pretty pink flowers, flowering freely all summer with little or no deadheading, along with Capitatum a darker shade of pink flowers, commonly used once in pot pourri. They too have used Lady Plymouth for her handsome foliage and Prince of Orange for the pungent sharp tang of orange zest from those leaves.

Take soft tip cuttings in late summer to bulk up your treasures, and over-winter your stock plants in your porch or greenhouse, keeping them on the dry side over winter and increasing the water and heat in late spring to encourage them back into growth. All appreciate a balanced weekly feed in spring, and feeding during the growing season will increase the flowering. Plant them somewhere where you will brush past or walk frequently so you can enjoy the scent; they are ideal for the hay-fever sufferers, because if you remove all the flowers you still have the delicious leafy aromas to enjoy.

So whether you call them ‘geranium’ or ‘pelargonium’, just be sure you have the scented ones, because they just have to be smelled to be believed.