Tried & Tested: Zinnias

If ever a summer-flowering annual had an image problem it's the zinnia. Most people have heard of them, yet few ever grow them. A common assumption is that they're tricky to raise and only survive to put on a decent show given rich soil and a particularly sunny, sheltered site. But is this really the case? Gardening Which? trialled 25 varieties at sites near Edinburgh, Leeds and London to find out how well they performed under a range of growing conditions. Each site aimed to raise 25 top-quality plants of each variety of the Mexican native from seed.