When severe frost is forecast, you would do well to cover some winter vegetables in the field. Opinions are divided about the choice of the appropriate type of covering material. The type of frost, whether or not in combination snow, will have a major influence on the result. The wind strength and the sensitivity of the crop to leaf breakage also play a role here.
Perforated foil provides the best protection against frost. but this foil flutters the most in a lot of wind and therefore comes off more easily. Some crops that are covered for a long time therefore clearly show more flutter damage under the perforated plastic. We have already experienced this with leeks, but a short cover period only during the frost period itself can limit the damage.
Fleece cloth will also flutter in a lot of wind, but that causes less damage and will not come off so quickly. Fleece cloth provides better frost protection than climate mesh but is more sensitive to cracks. The cloth is often broken after a single use.
Climate networks, such as Howicover, won't fly even when there's a lot of wind. Covering with climate network alone is sometimes insufficient in dry frost and still causes some frost damage.
When forecasting severe frost, you do not always have enough time to cover much more. With leeks, it is possible to cover them in advance and for a long time. Klimaatnet is a grateful material because it does not cause flutter damage and does not come off easily. To better protect against severe frost, it may be useful to double cover with a climate net on top of perforated foil. Experience with this double cover shows us that the perforated foil also stays in place better without causing flutter damage to the leek. Leaving this double cover for a long time had no adverse effect on leeks.
Published in Proeftuin News 21, December 2020
