How to Grow Queensland Arrowroot in New Zealand
Updated September 2026
A tall, leafy clump with starchy roots, for the warm frost free north
Queensland arrowroot, also called achira, is a relative of the ornamental canna. It grows into a clump of tall stems with broad, paddle shaped leaves and small red flowers, and underneath it forms large, knobbly rhizomes full of easily digested starch.
It is an easy plant where it suits. The roots can be cooked like potato or washed to extract a fine flour, the young shoots are edible, and the big leaves make useful bulk for the compost heap or feed for poultry.
Where Queensland Arrowroot Grows in New Zealand
Queensland arrowroot suits only a few warm regions. In Northland and Auckland it grows as a summer clump; plant rhizomes in October or November. In Waikato and the Bay of Plenty it is marginal and worth trying only on the coast of the Bay of Plenty: plant in November and mulch the clump well before winter.
It is not suited anywhere else. Frost kills the tops, and where winters are cold the plant struggles to come back. That rules out the Central North Island, Wellington and the lower North Island, Nelson and Marlborough, Canterbury, Otago and Southland and Central Otago. Choose your region below for local planting months.
Forms to Look For
Queensland arrowroot is rarely sold by variety name. It is usually passed between gardeners as rhizome pieces or sold as plants by specialist edible plant nurseries.
Green leaved form
Plain green leaves and stems, with small red flowers.
Purple stemmed form
Leaves edged or flushed with purple on dark stems. It is grown the same way and makes an ornamental clump.
Planting
Plant rhizome pieces or potted plants in spring once the soil has warmed, October or November in Northland and Auckland and November on the Bay of Plenty coast. Arrowroot grows in sun or part shade in moist, fertile soil with a pH of about 5.5 to 7.
- Plant rhizome pieces with at least one bud about 10 centimetres deep.
- Space plants about 1 metre apart. A clump grows 1.5 to 3 metres tall.
- Choose a sheltered spot, because wind tears the big leaves.
- Water in and mulch well.
- Arrowroot also grows in a large pot at least 50 centimetres wide, which you can move to shelter for winter.
Care
Pollination. You grow arrowroot for its roots, so no pollination is needed. The small red flowers may set seed, but new plants are always started from rhizome pieces.
Watering and feeding. Keep the soil moist through summer, when the clump grows fast. Feed with compost or a balanced fertiliser in spring and again in midsummer.
Winter. In the warm north the clump carries on through a mild winter or dies back and regrows in spring. In marginal gardens, cut back the frosted tops and cover the base with a thick mulch.
Spreading. The clump widens each year. Lift and divide it every few years, replanting young pieces and eating the rest.
Pests and Diseases
Queensland arrowroot is a hardy plant with few problems.
- Slugs and snails: Chew new shoots as they emerge in spring. Protect young growth.
- Frost: Blackens and kills the leaves and stems. Mulch the base in marginal gardens.
Harvest and Storage
Rhizomes are ready about ten months after planting, from late autumn into winter, when the leaves start to yellow. Dig around the edge of the clump and take what you need, leaving the rest in the ground, where it keeps until you want it. Young rhizomes are tender; old ones become fibrous.
Peel and cook the rhizomes like potato, by boiling or roasting. To make starch, grate the peeled roots into a bowl of water, squeeze and strain out the fibre, then leave the milky water to stand. The starch settles to the bottom. Pour off the water, rinse the starch once or twice more, and dry it thoroughly before storing it in a jar.
Track Your Arrowroot
Add Queensland arrowroot to your garden in the Planting Season app and get reminders for planting, mulching and harvest.
Open the App →Frequently Asked Questions
Where can Queensland arrowroot grow in New Zealand?
It suits Northland and Auckland, and is marginal on the Bay of Plenty coast. It is not suited to any other region, because frost kills it back and it will not come away again reliably.
When should I plant arrowroot?
Plant rhizomes in October or November in Northland and Auckland, and in November on the Bay of Plenty coast.
How do you harvest arrowroot?
Dig rhizomes from the edge of the clump from late autumn into winter, about ten months after planting, when the leaves start to yellow. Leave the rest in the ground and dig as needed.
Can I feed arrowroot leaves to chickens?
Yes. The leaves are used as feed for poultry and other stock, and they also make good bulk for the compost heap.
