New Zealand’s geographical isolation from other land masses for
the last 80 million years has meant that our native plants have evolved
in isolation from other vegetation, producing unique forms. Most of our
native fauna (80%) is endemic, i.e. only found in New Zealand. However,
the arrival of people about 1000 years ago had a dramatic effect on native
forests, birds and freshwater wetlands, reducing their biodiversity considerably.
This decline in biodiversity is of great concern to those who place a
high value on our native flora. Further decline can be prevented by promoting
the growth of native plants in the natural environment as well as garden
Growing native plants in your home
Buy native plants from the nursery because they have been selected
for their good form and have been well established for the garden setting.
Purchase plants that suit the environmental conditions in your area.
Consider the size of your garden and how much time you are willing
to spend on taking care of your plants because the time required varies
with different types of plants.
Give your plants good soil, nutrients, water and shade, as required.
How to grow natives
Natives in soil
Water or soak the root ball thoroughly before planting. Dig a hole
twice as big as the root ball to give the root system enough space
to grow in and establish quickly. Add compost, organic matter, slow
release fertiliser, or blood and bone and then mix. Remove the cover
or container surrounding the root ball and loosen the root ball gently
with your fingers to release the roots. Stretch out the old roots
so that they are able to reach the soil mixture. This will encourage
new root growth. Then place the root ball inside the hole and cover
it with firm soil up to or slightly above the surface of the ground.
If planted too deep, the plant will eventually die from pests and/or
disease. Water well and cover the root zone with about 5 cm of mulch
(e.g. compost or organic matter) to help keep the roots cool and the
Water the plants, i.e. water as required to promote root elongation.
Regular fertiliser and pruning are generally not necessary, but a
slow release fertiliser or blood and bone can be applied and plants
pruned in early spring and summer
Natives in pots
Select a pot that is twice as big as the root ball of the plant
and has drainage holes in its base. Soak or water the root ball thoroughly.
Cover the drainage holes at the base of your pot with stones or a
piece of broken pot to allow drainage and prevent your plant from
drowning when you water it. Cover the base of the pot with commercial
soil mix that contains slow release fertilisers. Loosen the root ball
with your hands and place the root ball inside the pot. Cover it with
firm soil to avoid the build-up of air pockets that will interfere
with the movement of water and air inside the pot. Water well. If
possible, raise pots above the ground, exposing the drainage holes
to ensure good drainage and avoid leaving your potted plants in water-filled
saucers otherwise plant roots may suffocate
Water frequently and feed using a slow release fertiliser or with
blood and bone, twice a year, preferably in late winter and again
in mid summer. Prune if required in early spring and summer
As environmentally aware gardeners, never collect native plants from
the wild and grow them in the garden. Firstly, plants taken from the wild
often make the worst possible garden material because the conditions in
which they have been growing are often difficult to duplicate in the home
garden. Plants from the wild also tend to suffer from transplanting shock,
and are often not the best specimens. Seed collected from plants in the
wild is also highly variable, again often producing poor specimens. Finally,
such collecting is potentially detrimental to the location they were obtained
from, if not illegal.
Some edible native plants
Native spinach, northern (Tetragonia tetraganoides) and
southern (Tetragonia trigyna) – the only native plant
sold as a vegetable
Cabbage tree – has edible crowns
Snowberries and Coprosma – has edible fruit
Climbing kiekie – has edible flowering bracts
Manuka, kamahi and rata – are used for honey production.
Pests and diseases of native plants
Not many native plants are prone to pests and diseases, unlike many cultivated
plants. However, they are prone to certain diseases, but most of these
are general such as damping-off fungi and the occasional rust. Few diseases
require special sprays, but a selection of those that do are described
Kills off many of the young attractively flowered cultivars of manuka
(Leptospermum scoparium), while kanuka (Leptospermum
ericoides) is only mildly affected. Manuka blight is caused by
a scale insect (Eriococcus orariensis) that feeds on the
sap. The black smut lives on its excretions (i.e. excess sap named
`honeydew’) and a soot fungus, Capnodium walteri, feeds on the
smut, blackening the excretions and reducing the photosynthetic capacity
of the plant. The plant dies from the excessive extraction of sap
caused by adult female and nymph scale insects.
The caterpillar of the native moth, Uresiphita polygonalis maorialis,
which is present throughout New Zealand, feeds on the leaves of kowhai
(Sophora), yellow tree lupin (Uresiphita polygonalis)
and occasionally gorse, clover and broom.
This insect was accidentally introduced from Australia so no parasites
or predators exist in New Zealand to control it. However, a parasitic
fungi (Myriangium thwaitesii) of E. orarienses kills
the insect by penetrating it with its hyphae (the vegetative structure
of many fungi). Spraying with summer oil or maldison combined with
a spreading agent can reduce the effect of the insect on your ornamental
Kowhai tends to recover from even the most severe attacks. Nevertheless,
any insecticide designed for chewing insect will help control the