Red is always tricky in even partial shade. If you've moistish soil, red astilbes and red lobelias (the perennial spire-shaped ones) might do you. And you can get some pretty reddish geums. There are also some varieties of hemerocallis (daylily) that are red. I'd suggest buying any of the above when in bloom, however, as reds can be very variable in exact colour, and you'd want to be sure you picked the 'reddest' ones! Whites and blues are pretty easy for shade, though blue becomes hard to get come July - later-flowering stuff tends to be any colour EXCEPT blue. Tradescantia, maybe. I'd suggest some white anemones for later in the year (look carefully though - different varieties vary a lot in height, though because the flowers kind of hover well above the foliage this may not bother you), and blue hardy geraniums. Perhaps annual bedding is the way to go to get late blues - bedding lobelia does ok in partial shade and goes well in tall narrow pots to give it a bit more presence. I use this with blue and white muscari bulbs underneath it in the pot for earlier flowers. They're lovely too, but rampant spreaders in the soil, so potted up are ideal and will go year after year. Theres also cerinthe major which grows easily from seed and does fine in partial shade too, so long as it isn't dry. General advice - try for clumps of things that are AT LEAST 2ft across, and use some of your plants more than once in the bed, to give it a unified, less bitty feel. Bx
