Posted: 01/04/2015 at 18:49
I have always struggled with rudbeckia, echinaceas, galliardia and the like on my much-improved clay soil. Those are all finicky plants and simply don't like growing in some areas, especially if it's somewhere with a lot of winter wet and/or a frost-hollow. However, there are plants which will give you equally gorgeous blooms such as dahlias (as long as you lift them in winter), delphiniums (both perennial and annual types), foxgloves etc. Another 'trick' is to grow young plants on in large 2-3 litre pots for a year or two before planting them out. Large mature plants fare much better in less-than-ideal conditions than small ones.