What are we focussing on during Winter?
If you think gardeners wind down over the winter months - think again! We make the most of the short days starting earlier and are thankful to experience more fine days than we normally would these last few weeks, as contending with too much rainfall can be problematic. We’re also lucky Te Awa Kairangi / the Hutt Valley region has a temperate climate to grow a number of crops in the field even if their growing capacity slows down with less sunlight hours.
These include our salad ingredients, root veggies, alliums and brassicas:
- Mustard mizuna
- Baby kale
- Spring onions and purplette onions
- Brassicas - Kale, Broccoli, Cauliflower, Red and white cabbage, Wong Bok (Chinese cabbage) and Pak Choi.
As you can see we still require the use of insect cloth to cover our field crops while they're young. While not used for insect pressure as much, the insect cloth provides enough protection from heavy rain, frosts and windy weather; as well as to deter birds such as sparrows. In fact, a couple of beds in our greenhouse have needed to be netted to prevent sparrows from scratching and eating young lettuce seedlings!
This greenhouse has 20x twelve metre long garden beds and at this time of year we grow mainly fast growing crops such as mustard and mizuna, lettuces, spinach and herbs such as coriander. Even though we can grow these in the field outside, it's reassuring to have crops undercover as a precaution if an extreme weather event were to occur. The good news is they also tend to grow somewhat faster than outside by 1-2 weeks.
Despite remaining in the greenhouse, our radish microgreens have slowed right down to 12-14 days - nearly twice as slow as they would in summer! But it hasn’t stopped us continuing to sow our winter crop seedlings such as pak choi, chinese baggage, sprouting broccoli. Our lettuces however do need that extra warmth with the use of heat pads but overall seedlings are germinating well.
We’ve also been inoculating / treating our brassica seeds with Trichoderma, a type of fungus that helps the plant to metabolise nutrients and to fight pathogens. When used as a seed treatment, the fungus has the ability to support seed germination and ultimately the plant’s health and growth once planted in the field.
When we go to plant these crops we have been careful not to fork the beds (using the broadforking method) with too much moisture in the ground, as this practice can do the opposite to what it is intended for and compact the soil.
Why get excited about Winter grown produce?
We’ve actually been admiring the beautiful frosty mornings - not just because of their visual beauty but the fact that frosts help make our veges taste sweeter!
Now that we have got a couple of frosts under our belt - root vegetables, brassicas and alliums such as leeks actually perform better nutrition wise. Plants like these become sweeter and tastier during a frost because they produce more sugar to tolerate a lower temperature without freezing.
Further to this, some vitamins and minerals have increased concentrations such as Vitamin C. Vitamin C levels were shown to be higher in spinach harvested in winter compared to when harvested in spring and summer/Autumn. This probably comes as no surprise as discussed in the Autumn edition, Vitamin C is sensitive to increases in temperature, breaking down more so when in contact with heat, light and water during cooking.
While Vitamin C is an important immune-boosting nutrient, and present in most of the winter grown vegetables and herbs - we also get excited about the fact that winter grown veg also contain significant levels of Iron (Fe)!
Winter vegetables with high Vitamin C and iron include cauliflower, broccoli, parsley, rocket, cabbages (red, green, Wong Bok/Chinese cabbage) as well as the trusty dark leafy green vegetables that are plentiful this time of year such as spinach, kale and silverbeet.
Iron is an important nutrient that helps make haemoglobin to transport oxygen around the body for our cells to make energy. We take a more in depth look at iron and how to optimise its absorption in food, with a particular focus on winter veggies, so stay tuned!