The 3 parts to good riparian design
Certain plants grow best in certain regions. If you’re unsure which plants are suitable for your area, contact your local nursery or regional council for advice on the best options. Dairy NZ also has great regional listings of plants: go to www.dairynz.co.nz/environment/waterways/ then click on ‘Regional Planting Guides’ at the top of the menu on the right-hand side of the page and choose the one for your region.
1 Outer margin Spacing: 1 metre wide
This includes dense, low-growing pasture species to trap sediment and nutrients, but also so it’s easy to prevent plants from shorting electric fencing or stock reaching plantings inside the margin.
2 Mid-margin Spacing: 1-2m Popular options:
cabbage trees, manuka Plant with taller trees and shrubs that shade the waterway which will reduce weed growth and create shelter for new seedlings to become established. Include vegetation that creates shade to help to keep water temperature stable and encourage fish and insects. Overhanging vegetation also provides a source of food for trout and native fish as bugs fall from vegetation into the water.
3 Channel margin Spacing: 0.5-1m Popular options:
toetoe, flax, gossamer grass, native sedges (eg, Carex species) and rushes (eg, Juncus species) This requires species that will tolerate sediment deposition, that don’t mind wet feet if an area is prone to flooding, and that will be able to ‘lay down’ in fast-flowing floodwaters. Native sedges and rushes can even survive if they are under water for a couple of days.