I find the winter garden a fascinating place to be and so different to the summer garden. There is more time in the winter garden, the life energy has slowed down and there is a gentler pace to everything. I love weeding in winter because once you have removed the weeds they take months to grow back. The soil also responds differently. While it may be dry it does not take much water to make it moist, and we find that a hand water is sufficient during the dry periods of winter, whereas in summer this is totally inadequate. In winter, while we may have periods that are quite dry the soil remains very cool and evaporation is at a minimum. According to Roger Hosking our local Weather Data Analyst “Soil water / soil dryness is a complex function of rainfall, temperature, evaporation and vegetation type” and I find this most evident in the winter garden.
Frost of course adds another dimension. According to the Bureau of Meteorology (BOM) "Frost occurs when the ground and ambient air cools down by the loss of heat to the atmosphere. This most commonly occurs under clear skies and with little or no wind. Clear skies favour the escape of radiation (heat) from the earths surface to space. Frost s a deposit of ice crystals formed on objects exposed to the air. Water vapour in the air freezes upon contact with an object that has a surface temperature below 0°C. Frost begins at ground level and gradually rises to higher objects. Crop covers can be used to manage the risk of frost by preventing the loss of heat during the night."
At Wynlen House we use crop covers to great affect in our garden. As I have said in an earlier post It’s officially Winter and your veggies Know it, there is about a 3° air surface temperature difference between our covered beds and uncovered beds. In light frosts this temperature difference can provide complete protection, of course temperatures below -3° will affect plants even if they are under cover. Cold temperatures and frost can freeze the cells in a plant, causing damage and interrupting the pathways for nutrients and water to flow. Cold hardy winter vegetables are less vulnerable and can withstand very cold temperatures and some frosting. Mind you our extended frost period of over 3 months (109 frost days) does provide some challenges to even the most cold hardy vegetable. The aim of using crop covers is not to grow vegetables out of season but to ameliorate the impact of severe frosts and enable some growth. The majority of winter or cold season vegetables will continue to grow at temperatures as low as 4°.
At the moment we are growing a range of Japanese and Asian greens that are doing extremely well (Ive got some photos of these below) and coriander also thrives in these cooler temperatures. We find that many of our customers are surprised that Asian greens cope well in the cold assuming that they require warm climates to grow. I often think about the Chinese who came to this area during the gold rush era who find their niche as market-gardeners. What vegetables did they grow? How did they provide crop protection? Were they growing the same vegetables that I am growing today?
It may be cold but a winter garden has much to offer including the time to ponder the practices of our market gardeners in times past and wonder about their response to our cool winter climate.
Our workshop in July deals with cover cropping, among other practices. You are most welcome to enroll.