Part or full shade and fairly heavy soil would suit these plants best. You will get flowers from April through to October and although the Pulmonaria is a blue flower, the silver foliage looks good all season and nothing else is in flower at the same time.
You will get a second flowering from the Astrantia if you cut it back immediately after the first flush of flowers has finished. Protect the crown of the Zantedeschia in freezing weather by covering with straw or a thick mulch of compost. This planting scheme with white flowers is perfect for heavy soil.
Download this PDF to print out: White & Green Planting Scheme