Tulip Blue Diamond - Double tulip A beautifully formed double tulip with purple-violet flowers (no Tulips are truly blue—yet). The darker coloring of Tulip Blue Diamond makes it a great companion for Double Tulip Angélique. Plant Tulips in well-drained, good garden soil. Full sun is recommended (at least 6 hours or more). Site: Best in shelterPosition: South or West facing, in full sunSoils: Rich but well-drained, sandy, light soilPlanting Period: September to NovemberFlowering Period: AprilPlanting: Depth 6” (15 cm), Spacing 5” (13 cm)Height: 40 cms