2 Ways to Reduce the Effect of Hail Nets on Apple Coloring

Editor’s Note: This article is part of our Hail Netting Complete Guide. Visit the Hub for the full breakdown of hail protection systems, installation, and selection guides.

Yes, hail nets can reduce apple colour — they cut the light that drives anthocyanin, the pigment that turns red and bicolour apples red — but the loss is manageable, and on green varieties there is none. Start with a light-passing net colour (transparent is best, covered in our net colour guide), then put the lost light back: lay reflective ground mulch (research shows 1.6–3.9× more reflected light and about 9% more well-coloured Class I fruit), and on the most colour-critical reds, use a net you can open for the final colouring weeks. Match the levers to your variety and you protect both the crop and its grade.

In Italy’s Val di Non, a violent hailstorm hit Trentino on 22 July 2021 and damaged roughly 500–600 hectares of apple orchards in a single afternoon. Events like that are exactly why growers turn to hail nets. But many hesitate over one concern: will the net dull the colour of the apples — and with it, the price? Here is why colour changes under net, how much it really costs, and how to keep it.

Why Does a Hail Net Affect Apple Colour at All?

Red apple colour comes from anthocyanin, and anthocyanin needs light to form — not just the amount of light, but the UV and blue wavelengths that switch pigment production on. A hail net reduces the light reaching the fruit, so it can produce fewer anthocyanins and show less colour. This only matters for red and bicolour varieties; green apples get their colour from chlorophyll and are not affected.

Two things decide how much a net actually costs you in colour. First, colour develops late — mostly in the final weeks before harvest, when cool nights and bright days drive the red. Lost light in that window costs the most. Second, the fruit that colours worst is already the fruit that sees the least light: apples on the shaded side and low on the inner branches. A net deepens that existing shade. So keeping colour is about putting light back during the colouring window — a separate question from the net’s overall shade rating, which we cover in our guide to the right shading rate for apples.

How Much Colour Do Hail Nets Really Cost You?

For a colour-critical red variety, an unmanaged dark net can move a slice of your crop from premium Class I down to Class II — and since colour sets the grade and the grade sets the price, that drop hits revenue directly. With a light-passing net and reflective mulch, the loss is small to negligible; on green varieties it is zero.

This is why colour is a commercial question, not a cosmetic one. Buyers pay for appearance: well-coloured fruit grades higher, fills the premium pack-out, and earns the top price. A net that protects 100% of your tonnage from hail but quietly downgrades 10–15% of a red variety on colour has only moved the loss, not removed it. Growers who net successfully treat colour as part of the netting decision from day one — they choose the net and the colour plan together.

Which Apple Varieties Are Most at Risk?

Colour risk depends entirely on the variety. Highly coloured and bicolour reds — Gala, Royal Gala, Cripps Pink (Pink Lady), Braeburn, Fuji and Red Delicious — are the ones to manage carefully. Green and yellow varieties such as Granny Smith and Golden Delicious are essentially unaffected, because their colour does not depend on anthocyanin.

How Do You Keep Colour Under a Hail Net?

First pick a light-passing net colour — transparent (crystal) shades only about 7% and is the best choice for colour-critical reds; we cover which colour to choose in our guide to hail net colour. But even a transparent net loses some light, and a darker net loses more — so the real work of keeping colour is putting that light back. Two levers do it: reflective ground mulch, and opening the net for the final colouring weeks.

1. Put the light back with reflective ground mulch

This is the lever that does the most work, and the one with the best research behind it. Reflective ground mulch bounces light off the orchard floor and back up onto the tree. Saskia Weber’s research found that 1.6 to 3.9 times more light is reflected when ground cover is used.^[1] The extra light improves skin colour most on the shaded side of the fruit and on apples lower in the inner canopy — exactly the spots that colour worst, and the spots a net shades hardest.

Meinhold’s study found the same: under black hail nets, the proportion of well-coloured Class I fruit was on average 9% higher in orchards using reflective mulch than in those without.^[2] Kerstin Funke’s trials confirmed reflective mulch improves fruit colour and maintains quality on the late-maturing bicolour variety Braeburn when laid in mid-September, about four weeks before harvest.^[3] The timing matters as much as the mulch: lay it for the final colouring window, not at the start of the season. This is why mulch works even under a black net you can’t change — it puts light back without touching the net at all.

2. Open or retract the net for the colouring weeks

Because colour develops late, some growers use net systems that can be opened or retracted — full hail cover through the storm season, then the net is opened or rolled back in the final weeks before harvest so the fruit gets maximum light exactly when colour forms. It is the most direct way to remove the shade penalty during colouring. The trade-offs are real: retractable systems cost more to build, add labour to open and close, and leave the fruit exposed if a late hailstorm arrives. Where late hail is rare and the variety is highly colour-sensitive, the grade it protects can justify the extra cost — but it is the lever to reach for last, after mulch.

Which Lever Should You Use — and What Does It Cost?

Choose the net colour once (see our colour guide), then stack the recovery levers by cost. Reflective mulch is a seasonal cost timed to harvest and does most of the work; an openable net is a capital decision for the most colour-sensitive, low-late-hail blocks. Here is how they compare.

When Is Colour Loss Not Worth Worrying About?

Not every block needs a colour plan. If you grow green or yellow varieties, net for hail alone — their colour is not anthocyanin-driven, so it won’t change. And where severe hail is frequent, the protection a net gives almost always outweighs a few points of colour you can recover with mulch.

Be honest about the trade-off in the other direction too. An openable system is real money; on a moderate-value block with rare late hail and a variety that colours easily, a transparent net plus reflective mulch usually gets you there for far less. Spend the capital where colour truly sets your price — high-value bicolour reds in a market that pays for top grade.

Questions to Ask Your Hail-Net Supplier About Colour

Once you’ve chosen a net colour, these questions tell you fast whether a supplier actually understands how to protect colour — not just sell netting.

1. Do you also supply reflective ground mulch, and what light reflectivity does it give? The supplier who only sells you the net is solving half the problem.
2. Can the net system be opened or retracted for the colouring weeks? Even if you don’t buy that option, the answer shows whether they understand late-season colour.
3. Is the net 100% virgin UV-stabilised HDPE? Light transmission stays consistent over the net’s life only with quality virgin HDPE — recycled material yellows and clouds, costing you light every season.

Frequently Asked Questions

Do hail nets really reduce apple colour?

They can, on red and bicolour varieties, because they cut the light needed for anthocyanin (the pigment that colours apples). The effect is manageable with a light-passing net and reflective mulch — and green varieties are not affected at all.

Can you keep apple colour without changing the net?

Yes. Even under a darker net you can’t easily change, reflective ground mulch puts light back onto the fruit — orchards using it under black hail nets averaged about 9% more well-coloured Class I fruit. Opening or retracting the net for the final colouring weeks recovers more. You don’t have to replace the net to protect colour.

Does reflective ground mulch work under hail nets?

Yes — research shows it reflects 1.6–3.9× more light into the canopy, and orchards using it under black hail nets had about 9% more well-coloured Class I fruit. It works best on the shaded side and the lower inner canopy, the fruit that colours worst.

When should I lay reflective mulch?

For late-maturing bicolour varieties like Braeburn, trials found laying mulch in mid-September — about four weeks before harvest — improves colour and maintains fruit quality. Time it to the final colouring window before your own harvest.

Can you open or retract a hail net to improve colour?

Yes — some growers use net systems that open or retract, giving full hail cover through storm season and maximum light in the final colouring weeks. It removes the shade penalty most directly, but costs more to build, adds labour, and leaves fruit exposed if late hail arrives. It suits high-value, colour-critical blocks in low-late-hail regions.

Do I need to worry about colour on green apples?

No — green varieties like Granny Smith get their colour from chlorophyll, not anthocyanin, so net shading does not reduce their colour. The colour concern applies only to red and bicolour apples.

References

1. Weber, S., et al. (2019). Reflective ground cover and light reflection in apple orchards. Journal of Plant Physiology, 233, 71–79. DOI: 10.1016/j.jplph.2018.11.010
2. Meinhold, T., et al. (2010). Reflective mulch and Class I fruit colour under hail nets. Scientia Horticulturae, 127(3), 447–451. DOI: 10.1016/j.scienta.2010.10.013
3. Funke, K., & Blanke, M. (2005). Reflective mulch timing for Braeburn fruit colour. Journal of Food, Agriculture & Environment, 3(1), 203–206.

Conclusion

Hail nets only dull apple colour if you let them. Start with a light-passing net colour, then put the lost light back: lay reflective ground mulch (around 9% more Class I fruit), and for the most colour-critical reds, use a net you can open at colouring time. Match the levers to your variety, and you protect your orchard from hail while keeping the colour that sets your price.

Want to protect your apples from hail without losing colour? Tell us your variety and region, and we’ll recommend a net colour, whether reflective mulch fits your block, and the right system — with a quote and a sample. Contact us for tailored advice.

By Kevin Lyu | EyouAgro — 28 years (since 1996) manufacturing hail netting for orchards worldwide, from a factory with 8 production lines.

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