Walls and fences are one of the most tricky areas of the garden to cover so, whether they face north, south, east or west. Toby Buckland comes up with suggestions for quick-growing climbing plants which will have them covered and looking good this summer. Carol Klein uncovers the colourful world of the Brassica family, plus Joe Swift joins Toby at Greenacre and shows us how to build a pond from recycled materials without compromising on design and quality.