Using plant guards

Plant guards are especially helpful if your site has pests or strong, drying winds. They are also a smart choice for high-value plants, or if you’re new to the planting process.

Because plant guards cost money and take work to maintain, ask yourself these questions before investing in them:

Is your site exposed or dry?
Are there rabbits, hares, possums, or sheep nearby?
Are your plants expensive or rare?
Are you worried about damaging the plants with weed killer or trimmer cords?
Are you new to planting trees?

If you answered YES to any of these, plant guards are a smart choice.

Types of plant guards

Every plant guard has pros and cons, and you’ll need to decide what works best for your site. When choosing what type of plant guards to use, think about how long you will need them to last and how you will dispose of them after use. Using plant guards alongside other methods like weeding, pest control and mulching will ensure your plants are well protected.

What it does

Guards made of netting protect seedlings from animals and physical damage. They’re cheap to make, long-lasting, and less likely to blow away because the wind passes straight through them.

What to consider

The guards must be taller than the animal you are guarding against. Guards made of netting do not improve growing conditions. They will not protect plants from frost, dry winds, or herbicide spray drift. You must remove the netting as plant stems grow to avoid ringbarking, where bark is stripped from the trunk, killing the tree.

What they do

Plastic plant guards come in 2 main types: rigid plastic guards and flexible plastic sheet guards.

Rigid plastic guards (made of tubes or corflute) protect against wind, frost, and herbicides while extending the growing season. They are reusable and long-lasting. Triangular designs resist wind better than square ones, making them less likely to blow away. Make sure rough guards don’t rub against the stem and cause ringbarking.

Flexible plastic sheet guards are a low-cost way to protect against herbicides and frost and extend the growing season. You can staple sheets together and support them with inexpensive fencing wire hoops instead of stakes. However, they provide little protection from wind and generally break down faster than rigid guards.

What to consider

Plastic guards should be removed once they have served their purpose. As they breakdown, they can contribute to microplastics, and they can wash away in flood-prone riparian areas.

What it does

Cardboard guards protect against herbicides, frost, and wind. Because they are biodegradable, these guards can be left on the site to break down into mulch.

What to consider

The lifespan of cardboard guards varies based on weight and surface treatment, meaning these guards may not last long in wet conditions. Weakened cardboard can collapse on plants and create a dark, gloomy, growing environment.

What they do

Wool felt or coir guards protect against herbicides, frost, and wind if staked properly. Being biodegradable, they can be left on-site as natural mulch that retains soil moisture.

What to consider

Wool felt or coir may degrade too quickly on very wet sites. If the guards collapse due to poor setup or bad site conditions, they could smother and kill the plants.

What they do

Tree trunk wraps or tubes protect against browsing animals and physical damage like weed-eaters. Long-lasting wraps or tubes, particularly the expandable types, keep loose organic mulch safely away from the trunk to prevent stem rot.

What to consider

Non-expandable covers need timely removal to avoid choking the tree trunk. Tall wraps can reduce herbicide damage, but don’t provide actual weed control.

What they do

Stakes keep your guards upright and secure. Bamboo poles are cheaper than treated timber. If you need timber stakes to last longer than 18 to 24 months, use treated timber. Natural wood will rot within a year or two and cause your guards to collapse.

What to consider

How many stakes you need depends on your site's wind levels and how long the guards need to last. You can skip traditional stakes by crafting simple hoops out of on-site materials like fencing wire.

Check up on your plants

Plant guards can trap heat and moisture around plants.
For species prone to fungal diseases, this can increase the risk of infection.

Match your guard to your main problem

Guard requirements

Your plant guards must block herbicide spray. They must also be strong enough to stop side shoots from growing out through the sides.

Alternatives to guards include:

• carrying out weed control before planting
• adding mulches
• using selective herbicides that target specific weeds without harming your seedlings
• weeding by hand instead of spraying.

Guard requirements

The guard must resist line-trimmers and brush-cutters. Visible guards help workers see the plants and avoid hitting them.

Alternatives to guards include:

applying physical obstacles like rock piles or tree branches
weeding by hand close to the stem
adding standalone stakes, flagging tape, or coloured paint for visibility
using mulch instead of line-trimmers.

Guard requirements

Narrow or triangular guards with rigid sides work best to protect your plants from wind. Use enough stakes to hold the guard deep in the ground and away from the plant. Mesh guards let air flow through, which reduces wind pressure and prevents the guard from blowing over.

Alternatives to guards include:

planting shelter belts 1 to 4 years before planting. These are strips of flax, shrubs, or trees that block wind and reduce damage to plants up to 10 times their height
constructing windrows with forestry slash (leftover branches and logs from cut trees)
stacking straw bales or tying wind-cloth to a nearby fence.

Guard requirements

Guards must be taller than the weeds they are protecting against. If you use weed mats, make them wide enough to stop weeds near the plant. Position them close to the stem so weeds cannot grow inside the guard competing for light and nutrients. Weed mats, coir, wool, and felt also save soil moisture by stopping weeds from growing underneath.

Alternatives to guards include:

removing weeds before and after planting
adding blanket mulch.

Guard requirements

Match the guard height to your target animal- 120 cm for sheep, 75 cm for hares and possums, and 60 cm for rabbits.

Choose a guard that doesn’t expose the lower stem or roots, which are vulnerable to damage caused by animals. You may need a mix of pest control methods and larger animals may need full site fencing.

Alternatives to guards include:

fencing the area
carrying out pest control before and after planting
applying animal repellents
using forest slash/branches or tall grass to protect the plants
planting plant species that animals dislike, such as tōtara, kānuka, or tutu.

Guard requirements

Use guards that create a greenhouse effect and a warm micro-climate. The sides must reach the ground.

Alternatives to guards include:

hardening off seedlings by exposing them to different weather outside first
choosing species that handle frost well
removing barriers that block cold air flow
cultivating the soil to raise the planting area (like ripping, bedding, or spot-mounding)
using branches and logs to create protected spots.

Have an exit plan

Know when to remove non-biodegradable guards so they don’t choke your trees or become litter.

Te mārama ki te ahungahere Understanding forestry

Whakamaheretia tō ngahere Plan your forest

Whakatōngia, whakatipuria Plant and grow

Te tiaki me te tope Care and harvest

Te mārama ki te ahungahere Understanding forestry

Whakamaheretia tō ngahere Plan your forest

Whakatōngia, whakatipuria Plant and grow

Te tiaki me te tope Care and harvest

Ngā rauemi me ngā māramatanga Resources and insights

Types of plant guards

What it does

What to consider

What they do

What to consider

What it does

What to consider

What they do

What to consider

What they do

What to consider

What they do

What to consider

Check up on your plants

Match your guard to your main problem

Guard requirements

Alternatives to guards include:

Guard requirements

Alternatives to guards include:

Guard requirements

Alternatives to guards include:

Guard requirements

Alternatives to guards include:

Have an exit plan

Related articles

Te tāmi kararehe kīrearea mō ngā ngahere Pest animal control for forests

Plant guards

Types of plant guards

Netting (plastic or wire)

Plastic guards

Cardboard

Wool felt or coir (coconut husk)

Tree trunk wraps or tubes

Stakes

Check up on your plants

Match your guard to your main problem

Protecting your plants from herbicide damage

Protecting against damage from line-trimmers and brush-cutters

Protecting your plants from wind damage

Preventing weeds from choking, smothering, and taking resources like water and soil from your plants

Preventing animals from browsing your plants

Stopping frost from harming your seedlings

Have an exit plan

Related articles

Te tāmi kararehe kīrearea mō ngā ngahere Pest animal control for forests