A south-facing balcony in Graz can hit 45°C at pot level in July. Most bedding plants from the supermarket give up by mid-summer. These twelve do not.
Herbs that love the heat
Rosemary, thyme, oregano and sage all come from Mediterranean hillsides and want exactly what a hot balcony offers: sun, wind and soil that dries out between waterings. Plant them in a gritty mix with a third horticultural grit.
Flowering perennials
- Lavender (Lavandula angustifolia ‘Hidcote’): compact, hardy, loved by bees.
- Gaura: flowers from June to the first frost and moves beautifully in wind.
- Catmint (Nepeta ‘Walker’s Low’): cut back after the first flush for a second one.
- Sedum and sempervivum: near-indestructible, good for shallow troughs.
Grasses
Stipa tenuissima and Pennisetum give movement and screening without the weight of shrubs.
The one rule
Use the biggest containers your balcony can safely carry. A 40-litre pot holds water three times longer than a 15-litre one, and the roots stay cooler.