Choosing the Right Plant Guard Height: 300mm vs 450mm

Quick Comparison

300mm Guard

  • Most popular size

  • Suitable for low to moderate browsing pressure

  • Cost-effective for large projects

  • Reliable early-stage protection

450mm Guard

  • Best for heavy browsing pressure

  • Reduces risk of top browsing

  • Ideal for exposed or high-risk sites

  • Improves survival in challenging environments

When planning a planting project in New Zealand, choosing the correct plant guard height can make a significant difference to plant survival and long-term success.

A common question is:
Should I use a 300mm guard or upgrade to a 450mm guard?

The answer depends largely on browsing pressure, site conditions, and the scale of your planting project.
This guide explains the differences so you can choose confidently.

Why Plant Guard Height Matters

Young native plants are vulnerable in their first 12–18 months.

In New Zealand, common threats include:

  • Hares

  • Rabbits

  • Pūkeko pulling or damaging young plants

  • Wind exposure on open sites

  • Spray drift from post-planting weed control

Collectively, these browsing pests can quickly damage tender new growth and reduce survival rates.

A guard that is too short may allow animals to nibble the top growth. A guard that is too tall (when unnecessary) can add avoidable cost across large numbers of plants.

Selecting the correct height improves survival rates and reduces the need for replanting.

300mm Plant Guards – The Most Popular Choice

The 300mm high x 150mm square EnviroGuard is our most widely used size across New Zealand.

It provides reliable protection for:

  • Farm shelterbelts

  • Exposed paddock planting

  • Upper riparian banks (where browsing pressure exists)

  • Council and restoration projects on open sites

  • Lifestyle block planting

In many situations, particularly where planting is away from the waterline, guards significantly improve establishment rates.

When 300mm Guards Are Suitable

Choose 300mm guards when:

  • Browsing pressure is low to moderate

  • Hares and rabbits are present but not in high numbers

  • Plants are not in extreme exposure

  • Budget efficiency is important across large-scale projects

For many planting sites, 300mm provides adequate early-stage protection while keeping costs manageable.

450mm Plant Guards – Best for High Browsing Pressure

If you have a known population of large hares or heavy browsing pressure, the 450mm EnviroGuard is the safer option.

Hares can nibble through the top of a 300mm guard if they are standing upright. Rabbits may also stretch for new growth. The additional height of the 450mm guard reduces the risk of animals reaching the top of the plant during the critical establishment phase.

When to Upgrade to 450mm

Use 450mm guards when:

  • Large hares are present

  • Browsing damage has occurred in previous plantings

  • Rabbit pressure is high

  • The site is highly exposed

  • Survival rates are critical (contract planting, council work, forestry blocks, paddock blocks)

In higher-risk environments, the increase in height can significantly improve plant survival and reduce replacement costs.

NZ Made, Biodegradable and Practical

All EnviroGuards are:

  • Made in New Zealand

  • Fully biodegradable

  • Designed to last approximately 12–18 months

  • Supplied pre-glued (no folding required onsite)

  • Installed using 750mm bamboo stakes

  • Compatible with biodegradable weed mats

Unlike plastic guards, EnviroGuards naturally break down once plants are established, reducing long-term plastic waste on farms and restoration sites.

Because they arrive pre-glued, installation is fast and efficient — particularly important for large-scale planting projects where labour time matters.

Protection Beyond Browsing

Both 300mm and 450mm guards also:

  • Provide protection from spray drift during spot spraying

  • Reduce wind stress on young plants

  • Help create a stable microclimate during early growth

This added protection supports stronger establishment and improves overall planting success.

Choosing the Right Height for Your Project

Not all riparian planting requires guards — particularly planting directly at the water’s edge.

However, on upper banks, exposed pasture margins, and areas with known pest pressure, guards can make a significant difference to establishment rates.

For farm-scale or block planting, selecting the correct guard height becomes a cost-versus-survival decision.

If replanting is expensive, upgrading to 450mm guards in high-browsing areas often makes financial sense.

For lower-risk sites, 300mm remains the most efficient and widely used option across New Zealand.

If you are planning a large planting programme and want to maximise onsite efficiency, Riverside Horticulture can also contract grow plants in biodegradable systems such as EnviroPots, reducing plastic handling and improving planting workflow.

Need Advice?

Every planting site is different.

If you are unsure which height to choose, consider previous browsing damage, local pest pressure, exposure levels, and the scale of your project.

Or get in touch to discuss your specific conditions.

Choosing the right plant guard height at the start can save time, labour, and replanting costs later.

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Efficient Installation Tips for Large Planting Projects

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How to Protect Native Plants from Hares & Rabbits