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Home > Our region and environment > Pollution Prevention and Compliance > On Site Effluent Systems (OSET) > Plants suitable for planting on wastewater disposal systems

Plants suitable for planting on wastewater disposal systems

Plants to be used over a land application area need to be chosen carefully.  The objective is to ensure that the whole of the land application area is covered.  This will optimise system performance and limit weed growth. 

Select large plants cautiously, as it may be difficult to prune or remove a tree which grows too large. 

There are a number of plants which can be used. You do not need to limit your choice to native plants, but the following is a list of natives which are suitable for wastewater disposal systems in the Bay of Plenty. We encourage you to use plants grown from locally sourced seed that are ecologically appropriate for the part of the region where they are being used.

The list is split into two parts: the grasses and ground covers should be used at the edges and the taller trees and shrubs planted in the middle of the land application area.

Grasses, ground covers and other plants

Astelia grandis (swamp astelia)
Large clump forming plant with wide, pointed bright green leaves.  Will form clumps up to 2m high.

Austroderia fulvida (toetoe)
Long strap-shaped leaves with red orange coloured veins.  The flower heads are cream yellow.  Natural distribution is Tauranga  and Rotorua and south of those centres.

Austroderia toetoe
The familiar toetoe with long weeping light green leaves.  Grows in clumps up to 3m high.  Drooping cream coloured plumes.

Toetoe Cropped

Blechnum novae-zelandiae (kiokio)
Also known as the palm leaf fern.  Fronds up to 2m long.  Young shoots are pink and turn green as they age.

Blechnum minus
Small low growing fern

Blechnum minus x B. novae-zelandiae hybrids
Hybrids of the two ferns listed above.

Carex dipsacea
Forms a dense clump of upright foliage light green and brown in colour.

Carex dissita (purei)
Also known as forest sedge.  Native sedge with dull green to reddish leaves about 500 mm tall.  Seeds occur on long stems.

Carex geminata
Vigorous native species that grows to 1.5 m tall.  Suitable for a larger area.  Green leaves have a sharp edge.

Carex maorica
Light green to yellow green tufted sedge.  Grows to 700 mm.  No rhizomes.  Prefers full sun.

Carex secta (purei, makura)
Endemic grass species that exhibits tall spreading tussocks.  May grow up to 3 m tall.

Carex virgata
Endemic grass species that forms dense light green tussocks up to 1m tall. 

Cyperus ustulatus (toetoe upoko-tangata, giant umbrella sedge)
Vigorous leafy sedge growing up to 1m in open damp places.

Dicksonia squarrosa (wheki, tree fern)
Tree fern up to 7m tall.

Elatostema rugosum (parataniwha)
Herbaceous plant up to 500 mm tall that spreads by rhizomes.  Bronze coloured foliage with serrated edge.  Prefers shade.

Gahnia rigida
Gahnia rigida
Robust perennial sedge forming yellow green tussocks to 2m tall.  Long erect leaves to 3m.  Prefers full sun.

Gahnia xanthocarpa
Robust perennial sedge forming dark green tussocks to 3.5 m tall.  Develops glossy black nuts.

Hypolepis ambigua (pigfern)
Large dark green fern with bristly brown hairs on stems.  Prefers shade.

Hypolepis distans
Small fern which creates a tangled mound 600mm high.  Fronds arise from a rhizome covered by dark red-brown hairs.

Juncus edgariae (wiwi)
Bright green to orange green rush which grows in tussocks to 600 mm high.

Juncus sarophorus
A hardy rush which forms tussocks to 1m.  Prefers full sun.

Lepidosperma australe (square sedge)
Blue green sedge with square stems to 2m tall.

Phormium tenax (harakeke, flax)
Fast growing clump forming flax with large stiff leaves to 3m.  Easily propagated from split fans or grown from seed.  Attracts birds especially tui.


Trees and Shrubs

Carpodetus serratus (putaputaweta, marbleleaf)
Lowland forest tree up to 7m tall.  Large bunches of cream coloured flowers appear in spring followed by black berries.

Coprosma areolata
Small leaved shrub species that grows to 4m tall.

Coprosma propinqua (mingimingi)
Small leaved shrub which grows to 3m.  Characterised by divaricating branches and dark blue fruit.

Coprosma propinqua x C. robusta
Common coprosma hybrids with leaf size and shape in a variable range between its two origin species.

Coprosma robusta (karamu, shining karamu)
Shrubs or small trees growing to 3 m tall with glossy green leaves.  Masses or orange-red fruit in autumn are attractive to birds.  Hardy plant.

Coprosma tenuicaulis (swamp coprosma)
Endemic species that grows to 3m tall.  Leaves pale green with slender branches.

Cordyline australis (ti kouka, cabbage tree)
Palm like in appearance with large heads of linear leaves and panicles of scented flowers.  Grows eventually to 12m.

Dacrycarpus dacrydiodes (kahikatea, white pine)
Relatively slow growing tree that grows to 40m.

Geniostoma rupestre (hangehange)
Common forest shrub with pale green glossy foliage, growing to 2-3 m.  Tiny flowers give off strong scent in spring.

Hebe stricta (koromiko)
Shrub or small tree growing to 2m.  Natural forms have white to bluish flowers.  Prefers full sun.

Kunzea ericoides (kanuka)
Fast growing small leafed tree to 5m.  Hardy.  Prefers full sun and well drained situation.

Laurelia novae-zelandiae (pukeatea)
Large upright tree (to 30 m) with attractive bright green foliage and distinctive whitish bark.  Fast growing.  Tolerant of some sun and frost.  Not tolerant of wind.

Leptospermum scoparium (manuka)
Shrub or small tree growing to 4m in height.  Common shrub varying in form throughout New Zealand.  Ideal to provide shelter for other plants as it is quick growing and hardy.  Requires full sun.  Tolerant of difficult conditions.

Melicytus ramiflorus (mahoe)
A fast growing but long lived tree to 7 m height.  Tolerates some frost, wind and sun.  Birds are attracted to the blue berries.  Requires shelter to establish.

Pennantia corymbosa (kaikomako
Dicksonia squarrosaSlow growing species that will reach 12m.

Pittosporum tenuifolium (black matipo)
Small tree with dark twigs bearing pale green shiny leaves.  Can grow to 5m.

Plagianthus regius subspecies regius (ribbonwood)
Small deciduous tree with interlacing branches and small leaves.  Grows to 6m.

Rhopalostylis sapida (nikau)
New Zealand’s only palm, with red berries attractive to birds.  Requires light shade, plenty of moisture and protection from wind when young.

Sophora microphylla (kowhai)
Divaricating and bushy tree with small green leaves growing to 6m.  Yellow flowers which attract birds and produce distinctive legume seed pods.

Sophora tetraptera (kowhai)
Tree growing to 10m with spreading habit.  Large grey-green leaves and yellow flowers.

Syzgium maire (maire tawake)
Attractive and moderately growing wetland tree to 12m with bronze foliage, large bunches of reddish fruit and distinctive whitish bark.  Tolerates some frost.

Vitex lucens (puriri)
Fast growing to 20m in fertile, open but sheltered conditions.