Dahlia imperialis

Giant dahlia or tree dahlia, Dahlia imperialis, is an enormous species growing to 3m, bearing thick, bamboo-like stems and large, elder-like leaves. It makes a fantastic foliage plant in its own right, however, if grown in a sheltered spot in a mild region, it may bear single, pink-purple blooms with orange-centres, from late October onwards. It’s a great choice for a tropical border but may also be grown in a large greenhouse or conservatory, where its chances of flowering are greatly increased.

Grow Dahlia imperialis in moist but well-drained soil in a sheltered spot in full sun. There’s usually no need to stake. As with all dahlias, lift the tubers and store over winter.