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Shade cloth percentage chart by crop

The short answer

Fruiting crops such as tomatoes and peppers want 30 to 50 percent shade cloth in summer, salad greens want 50 to 60 percent, and rooting cuttings want 70 to 80 percent. Choosing one shade percentage for a whole greenhouse is usually wrong, because a lettuce bench and a tomato bed under the same cloth cannot both be right.

Fruiting crops
30 to 50 percent
Salad greens
50 to 60 percent
Propagation
70 to 80 percent
Crop groups
11 listed

Researched from published specifications and verified owner reviews · Updated 2026-08-16

Shade cloth is rated by the percentage of light it blocks, so 50 percent cloth transmits about half the light that falls on it. That rating is a nominal figure measured on new material at a specific angle, and real transmission varies with sun angle, cloth tension and how dirty the cloth has become, so treat the percentage as a class rather than a precise value.

The reason a single figure for the whole house is usually wrong is that crops differ by a factor of five in the light they want. A tomato canopy will use everything a summer sky provides and asks only that leaf temperature stays survivable. A tray of cuttings with no roots cannot transpire fast enough to cool itself and will scorch at a third of that light.

Figure 1. Shade percentage and daily light integral target by crop group · 11 rows
Figure 1. Shade percentage and daily light integral target by crop group
Crop groupSummer shade percentageTarget DLI, mol/m2/day
Tomatoes, peppers, eggplant 30 to 50% 22 to 30
Cucumbers, melons, squash 30 to 50% 20 to 30
Strawberries 30 to 40% 17 to 22
Lettuce and salad greens 50 to 60% 12 to 17
Spinach, kale, chard 40 to 60% 12 to 17
Herbs, basil 30 to 50% 12 to 20
Seedlings and transplants 50 to 60% 10 to 14
Rooting cuttings 70 to 80% 4 to 8
Geraniums and bedding flowers 30 to 50% 12 to 20
Orchids, phalaenopsis 70 to 80% 4 to 6
Ferns and shade foliage 70 to 80% 3 to 6
Shade percentages are for peak summer at mid latitudes. Daily light integral targets are the ranges published in horticultural literature for good growth; below the range growth slows, above it the crop needs more water and eventually photoinhibits.

What shade percentage should you buy if you can only buy one?

Fifty percent, in almost every case. It is the setting that suits fruiting crops through their hottest weeks without costing them yield, it is survivable for greens, and it is the most widely stocked rating so replacements are easy to find. The BELLEBILL 50 Percent Shade Cloth, 10 x 12 ft is the standard hobby size with grommets already fitted, which matters because cloth without grommets tears at every tie point within a season.

Buy the second one for propagation rather than for the house. A small piece of 70 percent cloth over a cuttings bench, under the 50 percent covering the roof, gives roughly 85 percent total shade on that bench alone, which is the correct figure for unrooted material, without darkening the tomatoes.

A seasonal shading schedule

Figure 2. When to put shade cloth on and take it off · 6 rows
Figure 2. When to put shade cloth on and take it off
SeasonTypical outside DLIActionWhy
Deep winter 5 to 15 mol/m2/day No shade at all, clean the glazing Inside DLI can fall under 5, which is below the minimum for lettuce, so every percent of transmission counts.
Late winter into spring 15 to 30 No shade, but watch seedlings Light climbs faster than temperature. Young transplants scorch on a bright cold day with the vents shut.
Late spring 30 to 45 Put 50 percent on the roof This is when a closed house starts exceeding 95 degrees F, which is where tomato pollen viability drops.
High summer 45 to 60 Keep 50 percent, add 70 percent over propagation Peak load. Shading is cheaper than any amount of fan capacity for the same temperature reduction.
Late summer into autumn 30 to 45 Remove propagation shade, keep roof shade Autumn crops are establishing and still need protection, but light is falling fast.
Autumn 15 to 30 Remove all shade Every day it stays on past this point costs winter crops light they cannot get back.
Outside daily light integral figures are typical mid-latitude values. Your own figures will differ with latitude and cloud, and the transition points matter more than the exact numbers.

Shade cloth colors and what they actually do

Black knitted cloth blocks light without changing its spectrum much and is the general-purpose choice. White or aluminized cloth reflects rather than absorbs, so it runs cooler at the cloth itself and reradiates less heat into the house, which makes it the better choice where the cloth sits directly on the glazing. Green cloth transmits proportionally more green light, which plants use least, so it is the least efficient choice for the same nominal percentage.

Aluminized reflective cloth is the most effective at reducing temperature per percent of light blocked, and it is also the most expensive. If the goal is specifically to lower house temperature rather than to protect a crop from scorch, it is worth the difference. If the goal is protecting cuttings, plain black at a higher percentage costs less and does the job.

Field tip

Outside the glazing beats inside it

Shade cloth fitted on the outside of the glazing stops solar energy before it enters the structure. The same cloth fitted inside stops the light at the crop but the energy is already in the house and has to be vented out. Outside mounting is measurably more effective at reducing temperature, typically by several degrees, though it is harder to fit and takes more wind load.

Shade cloth or whitewash?

Whitewash, meaning a proprietary greenhouse shading paint applied to the glazing, has one genuine advantage: it is cheap per square foot on a large house and needs no fixings. Its disadvantages are that it is all or nothing, it cannot be removed for a cloudy fortnight, it washes off unevenly, and on twin-wall polycarbonate it is hard to remove without scratching. On a hobby greenhouse, cloth wins on nearly every count. The full comparison is in shade cloth versus whitewash.

Shade cloth by percentage

Four ratings covering the whole range in the chart, from fruiting crops through to propagation benches.

Fixing shade cloth so it survives a season

The fabric almost never fails. The tie points do. Shade cloth is a sail, and a 10 by 20 ft sheet in a 30 mile per hour gust exerts hundreds of pounds of force concentrated at whatever is holding it. Three rules follow. Use every grommet, not every third one. Tie with something that has a little stretch, such as bungee loops or elastic cord, rather than something rigid that transfers the whole shock load into one hole. And tension the sheet properly: a loose cloth that can flap will destroy itself and can scratch polycarbonate as it moves.

On a polycarbonate house the simplest method is a continuous batten along each eave with the cloth trapped under it, and elastic ties down to the frame at intervals. On a film tunnel, running the cloth over the hoops and pinning it at ground level with heavy steel landscape staples works and is easy to remove. Avoid anything that puts a hard point load on the glazing itself.

What shade cloth does not fix

Shade cloth reduces the light and therefore the heat load, and it does not do anything about three related summer problems. Understanding the boundary keeps you from buying more cloth when the problem is elsewhere.

Figure 3. Summer problems and whether shade cloth is the answer · 7 rows
Figure 3. Summer problems and whether shade cloth is the answer
SymptomActual causeDoes shade cloth help?What does
Peak temperature above 100 degF Solar gain exceeding ventilation capacity Yes, substantially Shade first, then exhaust airflow from the CFM chart.
Tomato flowers dropping without setting Pollen non-viable above about 95 degF, or humidity outside 40 to 70 percent Yes, indirectly Shade plus ventilation to hold the peak down, plus hand pollination in the morning.
Leaf scorch on young transplants Direct beam light on tissue that cannot transpire fast enough Yes, this is exactly what it is for Higher percentage cloth over the propagation bench specifically.
Wilting at midday despite wet soil Transpiration exceeding root uptake, a water transport limit Partly Shade reduces demand, but the root cause is usually root volume or salinity.
Bitter lettuce and bolting Temperature and daylength, not light intensity alone Partly Shade helps, but bolt-resistant varieties and succession sowing matter more.
Blossom end rot on tomatoes Irregular calcium uptake driven by irregular watering No Consistent irrigation, which means a timer and drip rather than hand watering.
Spider mite outbreak Hot dry conditions favor mites over their predators Slightly Raising humidity, damping down, and biological control.
The pattern is that shade cloth is the correct first response to anything caused by radiant load, and the wrong response to anything caused by water management or biology.

Match the percentage to your latitude and season with the shade cloth calculator, check the light your crop actually needs against the DLI targets chart, see where shade sits in the wider cooling strategy in cooling a greenhouse in summer, and read the fruit-set problem in pollination in a greenhouse.

Related on this site

Common questions

6 answers

+ What percentage shade cloth for a greenhouse with tomatoes?

Thirty to 50 percent through the hottest part of summer, and none at all outside it. Tomatoes want a daily light integral of roughly 22 to 30 moles per square meter per day, which is near the top of what any crop uses, so the shade is there to control leaf temperature and pollen viability rather than to reduce light. Above about 95 degrees Fahrenheit tomato pollen becomes non-viable and fruit set fails.

+ Is 70 percent shade cloth too much for vegetables?

For fruiting vegetables, yes. Tomatoes, peppers, cucumbers and melons under 70 percent shade will grow leaves and set poorly, because they are being held well below their light requirement. Seventy percent is correct for rooting cuttings, for hardening-off benches and for deep-shade ornamentals such as ferns. Leafy greens sit in between and do well at 50 to 60 percent.

+ Should shade cloth go inside or outside the greenhouse?

Outside, wherever it is practical. Cloth on the outside stops solar energy before it enters the structure, so the heat never has to be vented out again, and the temperature reduction is measurably greater, typically by several degrees Fahrenheit. Cloth on the inside still protects the crop from scorch but does much less for house temperature. Outside mounting takes more wind load, so fix it properly.

+ When should I put shade cloth on a greenhouse?

When the house starts routinely exceeding about 90 degrees Fahrenheit with vents fully open, which at mid latitudes is usually late spring. Do not fit it earlier: light climbs faster than temperature in spring, and shading early costs your crop light during the weeks it is establishing. Take it off as soon as peak temperatures fall back, because autumn and winter crops need every percent of transmission.

+ Does shade cloth reduce greenhouse temperature?

Yes, substantially, and it is the cheapest cooling available. Fifty percent cloth on the outside of the glazing typically reduces peak house temperature by 10 to 15 degrees Fahrenheit, which is more than most hobby exhaust fans achieve and costs a fraction as much. That is why shading is the first stage in any greenhouse cooling strategy and forced ventilation is the third.

+ What is the difference between knitted and woven shade cloth?

Knitted cloth is made from monofilament loops, so a cut or a tear does not run, and it is lighter and easier to handle. Woven cloth is denser, blocks light more uniformly, and generally lasts longer, but it frays when cut and needs its edges finished. For hobby greenhouse use knitted cloth with factory grommets is the practical choice, because the failure point is nearly always the tie point rather than the fabric.

Working out the figures for your own house and season? The Greenhouse Build & Growing Planner is the paid version of these pages: 8 printable worksheets you fill in with your own numbers, plus the full PDF, $29.