Nothing beats Dahlias for adding a colourful splash of interest to your garden. Dahlia Cactus varieties are classic and Dahlia Cactus Orfeo is especially stunning, with gorgeous spiky purple coloured flowers, that combine beautifully with almost anything. As with all Dahlia’s, they grow best when planted in a sunny spot in the garden, when the ground is starting to warm. An area that receives morning sun being the best.