Have you ever filled a plastic container to the brim with water and placed it into the freezer? If you answered yes, you will no doubt be mindful of the bulging, even exploding, that occurred as the water froze. Why? Because water expands when it freezes. Keep that in mind as we look further at frost. Frost is a weather phenomenon that many people fear, particularly those with plants considered "tender" leafed. Funnily enough, these often include Summer vegetables such as tomatoes, pumpkin vines, capsicums, or even lemons and lime trees, particularly the new growth. Seemingly overnight, green leaves can be turned into a brown, lifeless mess as a result of frost. When frost pays us a visit, it effectively freezes the water located within the plant cells, causing the cells to expand (like the water in the container), stretching the cell walls. This often leads the cell walls to overstretch and burst (like the container itself), and once that happens, there is no chance of revival for those cells. However, there are certain plants which have adapted to not only survive, but thrive in frosty conditions, and these include many of the seasonal vegetables grown by Heirloom Naturally. Many root vegetables (carrots, beetroot, turnips, celeriac, radish) have developed a unique way to stop their cells from expanding to the point of rupture, by converting starches located in their cells into sugars. As the plant detects a decrease in temperature, it takes starch, normally stored for energy and growth and converts it into a solid. In this case, a sugar. In doing so, the liquid space within the cells is decreased, and the plant has protected its cells from freezing. The added bonus is deliciously sweet vegetables, with no additional work (perfect!). Winter carrots are divine! Turnips turn into a delightful treat and even leafy greens, such as kale, broccoli and spinach move into a taste sensation of their own. If you have heard your loved ones say "I don't like kale", now is the time to give them a taste again. Tender, young frost sweetened kale leaves - oh my! And in the case of Red Russian kale, or scarlet kale, the leaves turn a brilliant purple to indicate they have begun converting those sugars - a colour that will hold during cooking provided they are not overcooked.
So, we salute you Jack Frost! You are welcome to visit us again during Winter, as often as you like.