How to Fertilize giant reed?
Balanced perennial feed every four weeks spring through summer growth

giant reed · Arundo donax
Also known as: distaff cane; great reed; reed grass; Spanish cane; vineyard cane; water reed
This plant is listed on Schedule 9 of the UK Wildlife & Countryside Act (Northern Ireland) as an invasive non-native species. Although not banned from sale, it is an offence to plant or cause these to grow in the wild IN NORTHERN IRELAND. Gardeners possessing them should undertake measures to control them. See RHS advice on invasive non-native species for further information
Balanced perennial feed every four weeks spring through summer growth