Poached egg plant

There is just one species of this Californian annual which is very simple to grow in almost any soil in a sunny spot. The bright white and yellow cup-shaped flowers create a cheerful patch of ground cover, with the apt name of poached egg plant. It's an asset in the vegetable garden as a companion plant to attract hoverflies which will feed on aphids and pollinate plants. It will self-seed freely and future generations will continue to appear and naturalise themselves over the area, germinating and flowering at different times. This can be imitated by sowing in autumn for flowers as early as April, and from spring to July for a long sequence of summer flowers. The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).