Toby Buckland is focusing on the high impact, low maintenance plants of the American prairie-style border at Greenacre. Alys Fowler plants the glorious, blousy peony and adds some luscious foliage to the cutting garden. In her garden at Glebe Cottage, Carol Klein is taking a look at the borage family. Plus Toby plants sweetcorn in his family garden and has tips on how to grow popcorn.