Polemonium yezoense ‘Purple Rain’ is quite a mouthful but well worth getting your tongue around. It’s a herbaceous perennial that has clusters of small blue flowers in fabulous tall dark stems in early summer. The plants grow as a mound of foliage consisting of tiny leaflets that look great all the time that they’re on show. It’s going to get to about a metre tall so will stand up proud in your borders to compliment your other perennials. Along with that when it comes to the cold Polemonium yezoense ‘Purple Rain’ is tough as old boots and will survive even the coldest winters that we get.