For me, these are the ultimate cottage garden plants whose majestic spires look great towards the back of the border in a range of shades - but if you want to make a real impact go for the deep blues and violets.

I love Black Knight, which is such dark purple that it looks almost black from a distance. For tall impact, go for the D. elatum Pacific Giants strain, which are large flowered. A good purple variety is King Arthur. For more subtle colour try Butterball, a cream variety, or Mullion, which is blue. These can grow between 5-8ft tall. Delphiniums do well in well-drained, fertile soil in a sunny and sheltered spot. Protect young plants from slugs, which love them.