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.
Plant calendar
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Plant
yes
yes
Flowers
yes
yes
yes
Dahlia and wildlife
Dahlia has no particular known value to wildlife in the UK.
