Wetland planting guide

What to plant in Canterbury lowland wetlands, planting plan and tips.

Get advice and help

Talk to Environment Canterbury and other groups listed on our wetlands contacts page about your goals. They can give lots of helpful advice - for example, what to plant, resource consents which might be required and options for help with funding.

Talk to your neighbours. Let them know what your plans are. Maybe you can each work on a site that can be linked to increase the area of wildlife habitat.

Get some help. See if your local community has any willing volunteers. Are there any local Forest & Bird or Fish and Game members, tree trusts or beautification societies, keen neighbours or school groups who want to help out?

Ask around your local community and your local council to find out if anyone is clearing native vegetation that you could salvage for your own site. If there is any pine forest harvesting nearby, the owners may allow you to transfer plants from the undergrowth that would otherwise be crushed. Don’t remove any plants from reserves or private land without permission.

Prepare a planting plan

With your free planting guide (pdf 116 kB) in hand:

Divide your wetland up into the three plant zones and make a list of the plants you can use in each zone. Take into account wind and drainage.
Choose plants characteristic of your wetland. Look at other wetlands in your area to see what grows there. Be aware that some of the plants may be plant pests or may have been planted but do not occur naturally in the area.
Check your list with your local nursery or Plant Pest Officers to ensure the plants you want are not potential plant pests.
Buy plants from nurseries that source plants from your district to ensure they are suited to your area’s climate and soils.
You may be able to grow some of your plants from seeds or cuttings taken from neighbouring wetlands—always seek permission before taking any plant material.
Decide where you want walkways, seats, and other features and plan for these.

Timing

Over summer, when water levels are low, put in any plants that grow in standing water right next to the water’s edge.

Hardy, frost tolerant species can be planted in autumn and frost sensitive species in spring.

Plants requiring shelter or shade can be planted one-to-two years later, once cover has developed. Or, if you have the time and resources, you can surround them with shade cloth until faster growing neighbouring plants are big enough to shelter them.

Site preparation and planting

Remember that native plants have poor tolerance of being grazed by stock. Areas must be fenced prior to planting in order to protect your investment.

Clear away grass and other plants in a one-metre circle around each planting site with a spade or a herbicide to ensure the new plants get enough light and nutrients. You can get information on suitable herbicides and suggested application rates from Environment Canterbury's plant pest officers. Also, check out our pests and weeds pages for online information.

Set plants out in sites suitable to their growing requirements, leaving space for them to grow. Ferns, rushes and small sedges can be planted three per square metre. Larger plants each need around 1.5 square metres each. If you have a very large area to plant, it is better to plant in clusters rather than space individual plants out across the site.

Dig a hole twice the size of the plant container, leaving some soft soil at the bottom. Set the plant in the hole and gradually fill in the soil, gently compacting it to remove air gaps. If a post hole borer is used, rough up the sides to allow the roots to penetrate.

Form a hollow around the base of the plant to trap rainfall on dry sites. Give the plants and surrounding soil a good watering. Water young plants over dry spells.

Staking the plants at this stage will make them easier to locate later. Tall, thin bamboo stakes highlighted with spray-paint are ideal.

Weeds and pests

Maintain plantings by clearing weeds around them for two-to-three years, until your plants are well established. Pests, such as rabbits and possums, need to be controlled, particularly during the seedling stage.

To find out more about wetland pest control see the page on wetland pest control.

More planting tips...

For a higher chance of survival, use larger potted plants. They are also less likely to be uprooted by pukeko.
Set your plants out in groups allowing about 1.5 m²per plant. The plants will soon shelter each other and begin to shade out surrounding weeds, making your job easier. More plants can be added to the edge of each group as time and resources permit.
In poor soils, a slow release fertiliser, well-rotted manure, or blood and bone can be added. However, this is not suitable if you are restoring a peat bog.
A 10 cm deep mulch (for example, untreated wood chips, compost, newspaper, old carpet under-lay, or rotted hay) can be used to help conserve water, keep weeds down and add nutrients.
In dry areas, leave a low grass cover around plantings for the first summer (until March) to help conserve water.
Fast-growing plants, such as manuka, can be used as nurse plants to provide shade for seedlings underneath.
You may find native plants popping up on their own once the stock have been removed from the site. Plants like flax attract birds such as tui, and they will bring seed of other species into the site for you!
Most plants listed as tolerant to standing water, including kahikatea, cabbage tree, and Juncus rushes, must first be planted in moist conditions before becoming flooded. The best time to plant these species is near the end of summer when water levels are lowest. This is particularly important for nursery-raised plants that have not been subjected to waterlogged conditions.
If your site is very wet, you can build low (20-30 cm) mounds to plant the young plants on. This will keep their roots above water until they have become used to the local conditions.

After three years, your plantings should take care of themselves and you can sit back and enjoy your wetland.

Keep a photographic record as you go, to remind yourself how much you've achieved.

Grazing near wetlands

It is best to keep stock away from wetland areas, as they can damage soils, disturb native plants and animals, and dirty the water. You can reduce damage to wetlands by grazing pasture near them in mid-summer to mid-autumn. Stock with uncontrolled access to wetland areas can:

Increase nutrient levels through their urine and dung
Pug and compact the soil
Cause erosion
Disturb the wildlife
Graze on and trample wetland plants
Lead to drying out
Open up sites for weed invasion
Carry weed seeds in their hooves, coats, or dung
Become trapped and be costly to rescue.

Grazing on pasture near wetlands can also cause pugging and affect the quality of water draining into the wetland, particularly during wet periods.