Shadecloth Percentages Explained: 30% to 90%

A shadecloth percentage is the share of sunlight the cloth blocks: 30% shadecloth stops about 30% of the light and lets about 70% through. Lower ratings (around 30–50%) are usually chosen for crops and nursery stock that still need plenty of light, and higher ratings (70% and above) for shade-loving plants, people and livestock. The right rating depends on the crop, the season and how harsh the sun is at your site.

Shadecloth (also written shade cloth) is one of the simplest forms of protected cropping. In much of Australia, summer sun and heat can stress crops even when water is available. This guide explains what the percentage, GSM and colour of a shadecloth mean, and how to compare rolls.

What does the shade percentage mean?

The percentage, sometimes called the shade factor or shade rating, describes how much light the cloth blocks. A higher number means a denser knit and less light reaching the crop. Two points are worth knowing:

It is not a temperature rating. Shading lowers leaf and air temperature under the cloth, but by how much depends on airflow, colour, height and the weather. A 50% cloth does not make it 50% cooler.
Ratings are set by the manufacturer. Compare like with like, using the rating stated for each product, rather than estimating density by eye.

Which shade percentage should I use?

These are common starting points used by growers and suppliers. Treat them as a guide, not a rule, and adjust for your crop variety, region and season.

Shade rating	Light let through (approx.)	Commonly used for
30%	About 70%	Fruiting vegetables, berries and sun-loving crops that need a little relief in peak summer; hail and wind screening where light must stay high
40–50%	About 50–60%	Leafy greens, herbs, seedlings and general nursery stock
60–70%	About 30–40%	Shade-tolerant ornamentals, propagation and hardening-off areas
80–90%	About 10–20%	Shade-loving plants such as ferns and orchids, people, animals, vehicles and privacy screening

Too much shade can be as much of a problem as too little. Fruiting crops grown under heavy shade may become leggy and yield less, so most growers choose the lightest cloth that prevents sunburn and heat stress.

What does GSM mean on shadecloth?

GSM stands for grams per square metre, which is the weight of the fabric. GSM and shade percentage are related but separate specifications. Heavier cloth generally means more material and a stronger, more durable knit. However, the shade rating also depends on how the cloth is knitted, so two cloths with the same GSM can have different shade ratings. When comparing rolls, check both figures, along with the colour and roll size.

Does shadecloth colour matter?

White reflects more sunlight and scatters the light that passes through, giving more even light under the cloth. It is often used over crops and in nurseries.
Black absorbs more sunlight and is a common, economical choice for general shading and windbreaks.
Green blends into gardens and landscapes and is widely used for screening and general shade.

For the same shade rating, colour changes the quality and spread of light more than the amount. If even light across the canopy matters for your crop, ask about white cloth.

Why choose knitted shadecloth?

Knitted shadecloth is made by knitting polyethylene yarn rather than weaving it. Knitted cloth can usually be cut to length without unravelling and is less likely to run if it is snagged. This is why it is widely used for tunnels, shade houses and agricultural structures. Look for cloth made for outdoor use with UV stabilisation, because Australian sun breaks down untreated plastics quickly.

How do I choose the right roll size?

Measure the structure, not the bed. Measure over hoops or along the frame, and allow extra for fixing and overlap.
Match the width to the span. A wider roll means fewer joins across a tunnel or shade house.
Plan the fixing. Eyelets make it easier to tie the cloth to frames and wires. Otherwise you will need clips, channel or tie points.
Allow for wind. Shadecloth catches wind. Secure it to a structure rated for your site and use suitable wire, twine and rope.

Can I use shadecloth together with greenhouse film?

Yes. Many Australian growers use film for rain and weather protection and add shadecloth over or inside the structure during the hottest months, then remove or roll it back in cooler weather. Diffused film also reduces hot spots on its own. See how to choose greenhouse film and greenhouse vs polytunnel for structure and covering options.