The rain is sheeting down outside as I write and I’m seriously wondering whether summer is over. I’m not alone in doing this, of course. We all know that these thoughts are a traditional part of the British summer!
Anyway, let’s assume, for the sake of argument, that scorching days are ahead. Which plants will do well in your garden and in mine?
Pelargoniums love hot, dry weather
Pelargoniums can cope with hot, dry weather better than many plants. They are very straightforward to grow: all most of them ask is plenty of light and a freely draining soil. They have very few pests and diseases. Water them occasionally (they hate damp conditions and poor air circulation) and if the weather is very dry, give them a good soaking. Feed them occasionally with potash-rich fertiliser (like tomato feed) and deadhead to encourage flowering.
Although they are often grown as annuals, pelargoniums can happily be perennial, given the right conditions. Help outdoor plants make it through the winter by taking cuttings, putting them in an unheated spare room or cold greenhouse, or putting them into a semi-dormant state.
Bedding, hanging basket, statement plants
There are several different types of pelargonium and each has a large range of varieties. There’s bound to be something that will suit you.
The zonal pelargonium has a horseshoe shaped mark (the ‘zone’) on the leaf. They are used for park and garden bedding displays but are also good indoors. Zonal pelargoniums will flower as long as there is good light and the temperature is at least 7-10°C. (A local café grows some inside against the front window as floor-to-ceiling perennials, in flower all year round.) There’s a huge range of fancy-leaf zonals, grown more for their coloured leaf marking than their flowers.
The regal (or show) and angel groups have shrubby growth, saw-edged growth and large bi-coloured ruffled flowers. These are best grown indoors or in partial shade outdoors. They make a good statement plant on a window sill.
The ivy-leaved pelargonium has fleshy leaves on trailing, slightly brittle, stems. In Britain these tend to be grown in hanging baskets and pots but they’re used as ground cover in countries with relatively dry and frost-free climates. I have these pelargoniums outside the back door: a white one in a dark green pot and two very dark red ones in black pots.
Finally, scented-leaved pelargoniums like the rose geranium* are mainly grown for their fragrant leaves, often distinctly lobed, toothed or incised, or variegated.
* Pelargoniums are commonly called ‘geraniums’ but that’s not really their correct name. True geraniums are hardy herbaceous plants.
What’s the long-range forecast for our pelargoniums and us?