Hardy geraniums are my thing this month. I don't mean the amazingly bright-coloured balcony and pot loving plants that bedeck France and the Med. which we usually call geraniums. Those are pelargoniums and are fantastic in summer gardens. Hardy geraniums are a much more British affair, with soft leaves and colours and a softer style of growth that can smother the weeds and create a fantastic carpet of colour and form. From early flowering in late spring and an amazing show in June, hardy geraniums go on flowering into the autumn.

Adding ‘hardy’ to the way we describe these lovely plants helps identify their key difference from pelargoniums (which are not hardy) and helps us gardeners choose and plant them in the right place.

With dozens of varieties offering different heights, flower and leaf colours, it’s easy to see why hardy geraniums are the most popular perennials in Britain.

Choosing hardy geraniums

hardy geraniums

Hardy geraniums - choose from among a range of varieties to fill your garden with flowers all summer. Sarah Buchanan.

Height: depending on the variety, hardy geraniums offer low, dense ground cover or a tower of leaves and colour up to and sometimes above 1m (3 feet) high.

Flower colour: pink, blue, white, and patterned flowers are all on offer.

Leaf colour, texture and shape: not just green leaves, but different shades of green, and some varieties have deep chocolate-coloured leaves. Some varieties are semi-evergreen (my favourite is Geranium macrorrhizum, with leaves changing from green to red and to green again beneath flowers in any of a range of pinks). Most varieties have bright, soft shaded leaves, a few are deep chocolate-coloured, and the leaves of Geranium renardii are grey-green, wrinkled and soft.

Where to plant hardy geraniums

All the varieties offer pretty and effective ground cover. They like sun or partial shade. Some prefer a dry soil. Knowing the eventual height is essential in planting to best effect.

Front of the border delights include:

The ‘cinereum’ group of hardy geraniums look good on sunny rockeries and along path edges. Tiny finely cut leaves support sturdy flowers in gorgeous colours. The flowers of ‘Ballerina’ are pale pink and patterned with deeper purple to pink veins.

In the middle:
Oxonianum offers salmon pink flowers (variety ‘Wageningen’) while ‘Orion' is a mass of lavender-blue flowers with purple veins and a white centre. The delicate white flowers of Geranium clarkei 'Kashmir White' are held high above lovely rich green leaves to create a light and airy feel.

hardy geraniums

Choose flower colours to tone or contrast in your garden or pots. Sarah Buchanan

And at the back:

'Rozanne', a vigorous plant growing to at least 60cm and up to 1m. The leaves are neat and lobed and the bowl-shaped violet-blue flowers have a white centre - and are pretty as a picture.  It's easy to see why this plant was one of those chosen by the BBC Gardeners' World team in the hunt for the programme's  Golden Jubilee Plant.

For stunning magenta pink flowers, choose 'Ann Folkard’, and enjoy the bright light green leaves beneath.

Simple care for hardy geraniums

Hardy geraniums

  • Trim back dead flower heads (and damaged leaves) to the base throughout the summer. Follow the flower head back with your hand and don't flinch when you see there is a lot of deciduous material to be cut away. It may seem harsh but the plants will reward you with a second round of flowering, so be bold and brave and water the plant well and stand back.
  • From autumn to spring, divide plants that have grown too big for their space. Throw the centre away and replant 3 or so chunks and give the rest away to friends.
  • Cut the stems of deciduous varieties back to the ground before new growth starts but leave evergreen varieties to spread as far as you want them (and root some of the spreading stems into pots to give away or plant elsewhere in your garden).