Donau and other agapanthus varieties grow from clumps of fleshy roots that generally are planted in containers or in the ground (in frost free climates) in early spring. Depending on weather conditions, the flowering time is June or July, sometimes into August.
Sited in full sun to part shade, Donau will sprout to a height of 18 to 24 inches. If the plant is grown in-ground or overwintered in a pot, the size of the root clump will increase and the plant will send up more stalks in subsequent years.
Agapanthus Donau was developed in the Netherlands and named after the Danube River ("Donau" in Dutch). Originally developed for the cut flower trade, Donau was noted for its prolific flower production and eventually made available for home gardeners.