It dipped to minus 5 last week and dawn to dusk sunshine could not shift the frost from our north facing slopes; nothing exceptional in January but it was our 20th frost this winter – about three times the average. It’s all down to weirdly persistent easterly winds which have brought us a gloriously bright and dry winter so far, in contrast to the dull, damp Devon mildness usually delivered by the prevalent moisture-laden westerlies.
A dry January is mostly good; it means less mud and fewer miserable days in damp oilskins, plus we need the cold to keep growth in check so our fields don’t empty of winter crops before new season crops are even planted. Some frost is OK but the cumulative effect wears a plant down, especially as it approaches maturity. Cauliflower and purple sprouting broccoli (PSB) can take a lot of frost
until the vulnerable flower heads start revealing themselves close to harvest, when even a light frost will cause damage. During the expected January and February frosts, we program PSB and cauliflower from our growers along the Devon and Cornwall coasts where the moderating effect of the gulf stream keeps the water above 8°C, normally enough to keep frosts a mile or two inland. Even so we have lost much of our early PSB and cauliflowers will now be short until the next mild spell.
Without flowers, cabbages, leeks, kale and spring greens can take a lot of cold but picking frozen greenery risks quality and is hard on the fingers. Harvesting this winter is all about making use of the few hours at the end of the day when the frost has melted; we pick like crazy and rush the crop into the barn before the frost returns. If your kale or cabbage has small translucent areas, this probably means we were a bit impatient; it’s a narrow line to tread.
The salads in our tunnels have so far survived unscathed. The harder frosts definitely get in there and the fine leaves can look very sad in the morning but the drier soil and dry leaves seem to save them so that by noon they stand up ready for harvest. With good light levels so far the winter salad bags have been good. We hope some mild weather will bring cauliflowers and PSB back into the boxes soon.