Pelagoniums (Scented Geraniums) are the hardest working plants for garden containers. In much of the country they flower most of the year and in a sunny and sheltered position can be hardy all year. In shades of burgundy, red, magenta, pale pink to white they can be sophisticated and urban, country garden or bright and fun. They are easy to get hold of at garden centres and nurseries and need minimal care (dead heading) and limited watering.
My garden in August colourful containers