How long will I need to maintain the plants?
It can take approximately three years for restoration plants to become established and shade out nearby weeds and long grass. This will of course be dependent on weather patterns and various plant growth rates.
After three years, plants need less maintenance, but you should still check occasionally for climbing weeds, willow, and gorse invasion.
How often will I need to conduct maintenance?
The number of maintenance visits required each year will be dependent on weather patterns (particularly seasonal rainfall) and growing conditions.
You should expect to conduct maintenance at least twice during the main growing season (spring to autumn).
Maintenance methods
Hand release
For smaller sites hand releasing (cutting and pulling back long grass) may be a practical option. Clear the weeds and long grass around young plants and inside guards before they are smothered.
Spread the cleared/cut weeds around the base of the seedling as a mulch.
Sturdy gloves and a hand cutter can help.
Here’s a good example of a hand cutter: Sharks against weeds
Brush cutters and line trimmers
These can be quick and effective as the weeds are left to decompose and create an organic matter layer which holds moisture and improves soil quality over time.
Simply cut the grass surrounding the plant guard back about 30-40 cm, taking care not to hit the plant or guard.
Spray
Spraying around the guards means that maintenance visits can be left longer and can be particularly effective on large sites. However, native trees and grasses are very susceptible to broad spectrum herbicides such as glyphosate.
If you choose to use sprays to control grass and weed growth, first contact your chemical supplier or rural services store for advice on appropriate herbicides and methods.
When spraying near water bodies (rivers, ponds, wetlands), take care not to allow spray or spray drift to make contact with water. Herbicide is toxic to some aquatic life.
Also, minimise area sprayed in these areas to ensure vegetative cover maintains soil stability. Exposing large areas of soil where there can be flooding can encourage erosion and slips.
Please keep in mind that herbicide spray-drift from nearby paddocks (that are being developed or resown) also has the potential to impact restoration planting survival.
Remember to:
- Follow the manufacturer's instructions and application rates carefully, including adding recommended surfactants (these often improve effectiveness)
- Aim for 0.5 metres of killed vegetation around each seedling
- Spray in a S-shaped pattern to avoid overlap i.e. along one row then the opposite way along the next row (spraying in a spiral pattern concentrates the spray)
- Take care that the chemicals do not go onto the desirable plant(s)
- Spray out from the plant/guard, not towards, to reduce the chance of spray on the plant
- Use a nozzle with a narrow fan of spray
- Consider a guard around the nozzle to protect your plant from spray. These can be bought or made at home using an old funnel or plastic bottle
- Spray on a still day to prevent spray drift coming in contact with yourself or other plants; and
- Spray grass while it is shorter, before it becomes long and rank, but while actively growing.
Watering
Please conduct regular checks of your plants during hot and dry conditions. If they begin to show signs of stress (wilting or browning) undertake watering efforts (as much as is practical).
Watering is best done thoroughly in the morning or evening, but not often (once a week).
If at any stage you become concerned about plant condition, please contact your catchment advisor.
Stock exclusion
Please check the fences and gates surrounding your planting area regularly, especially after flood events.
Replacement plantings
Some plants may not survive the first few years. Consider adding plants to fill any gaps.
You can also add in diversity once your initial plantings are established.
Some successional species (larger trees) require the shelter of coloniser species (native grasses and shrubs) to survive and are better planted later in your project.
Pest animal control
An inspection of pest infestations should be carried out before planting.
If significant pest sign is evident, seek professional advice regarding suitable pest control options prior to planting.
When checking your plants, keep an eye out for pest animal signs. Possums, rabbits, and hares can target restoration plantings. Rabbits browse plants, whereas hares can nip the stems off.
Remember that rabbits are a ‘sustained control’ pest under Otago’s Regional Pest Management Plan and all landowners are required to control feral rabbits on their land – for more detail on the rules and control methods, see our rabbit Pest Hub page.
You may also live in an area where there are larger pests including feral deer and pigs.
Ongoing pest control maybe necessary to maintain pest levels. Regular night shooting and trapping near planting sites help to keep in check.
Willows
Chemical ringbarking using a weed-gel or paste has been shown to be successful on willow saplings and small trees (contact your chemical supplier for advice on appropriate herbicides and methods).
There is also the option of drilling holes in the base of large trees and filling with a chemical herbicide.
This allows the tree to die standing and provides a perch for native birds that can bring in surrounding native seed.
If the tree is too big or there is a large infestation, tank or aerial spray can be the most practical way to control willows (of course taking care there’s no spray drift near plantings).
Mechanical removal of riparian willows (e.g., by using diggers) may require a resource consent – see here for more information.
Broom and Gorse
Cut and paste using a weed gel/paste. Large infestation can be sprayed with a knapsack or spray tank (of course being careful there’s no spray drift near plantings).
In some sites larger woody natives can be planted amongst gorse (which acts as a good nursery plant).
Over time the natives shade-out the gorse.
Gorse and broom are subject to the Regional Pest Management Plan as ‘sustained control’ pest species. For more detail on their regulatory status and control methods, see our Pest Hub pages for gorse and broom.
References and more information:
Dairy NZ Plant Maintenance Guide
Sustainable Business Network Plant Maintenance Guidelines
Taranaki Regional Council Plant Maintenance Guide
Trees that Count
How to maintain and monitor your planting projects - video