A late frost or an early freeze can wipe out a season’s worth of seedlings, blossom or tender crop in a single night. Frost protection netting is a cheap, reusable defence — but it works by trapping warmth, not by being thick, so the spec matters more than most growers expect.
Frost protection netting does not generate heat — it traps the radiative warmth the soil releases at night. During the day the ground absorbs heat; at night it re-radiates it. A net or row cover held just above the crop slows that heat from escaping, keeping the air underneath a few degrees warmer than the open field. That small difference is often the line between a crop that survives and one that is wiped out.
The net needs to be light enough to drape and remove, dense enough to hold warmth. 30–50 gsm floating row cover is the standard for light frosts; 50–70 gsm for colder nights and windy sites. A fine, dense mesh holds more warmth than an open one, but blocks more light — so a frost net used in daylight should be breathable enough to let light through to the plants. See our ground cover netting guide for the woven vs knitted choice.
| Condition | Frost netting | What you actually need |
|---|---|---|
| Light frost (-1 to -3°C) | Effective alone | 30–70 gsm row cover or net |
| Hard frost (below -3°C) | First layer only | Add poly tunnel or cloche |
| Freezing wind | Effective | Dense net plus windbreak |
| Blossom protection | Effective | Light floating cover over canopy |
The honest limit: frost netting protects against light frosts and chilling wind. Below about -3°C it is the first layer, not the whole answer — pair it with a poly tunnel, cloche or hoop house for hard freezes. Set expectations to the spec, and the net does its job every time.
Cover before dusk on nights a frost is forecast, so the trapped warmth is already building as the temperature drops, and remove it in the morning once the air warms, so the crop gets full light. Hoop the net over the row rather than laying it flat on the crop — a net touching the leaves transfers cold, while a net held even a few centimetres above traps a warmer air layer. Anchor the edges against wind, and the same net lasts season after season. Our nursery netting guide covers frost covers for propagation stock.
Typically 2–4°C of protection against light frost. It traps radiative ground warmth, so the gain depends on how cold it gets and how dense the net is. It is a first line of defence, not a heater.
30–50 gsm for light frosts, 50–70 gsm for colder nights and windy sites. Denser nets hold more warmth but block more light, so use them only at night where possible.
No. Hoop it a few centimetres above the crop. A net lying directly on the leaves transfers cold; one held above traps a warmer air layer and protects better.
Before dusk on nights a frost is forecast, and remove it in the morning once the air warms. Covering early lets the net trap warmth as temperatures fall.
Hoop the net above the crop and cover before dusk — frost netting traps warmth, it doesn’t generate it. Tell us your application and we will spec the right net, GSM and size.
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