A bit about frost - beautiful and mischievous.from the June newsletter
We can usually see it coming. A clear evening with little wind during the winter months means a brisk night ahead. When there are no clouds, warm air escapes into the atmosphere, creating an inversion layer and trapping cold air close to the ground. When the night is long and cold and the temperature at ground level is below freezing, we get frost.
Your soil is always radiating heat, but during the day the sun replenishes this loss and then some. On a cool, clear night this precious warmth shoots skyward, radiating heat faster than even the air itself. This means your crops and soil actually cool the air trapped by the inversion layer close to the ground, not the other way around. This explains why temperatures near the ground can be up to 4 degrees cooler than the overnight low, which is measured just above the ground. Interestingly, the lowest temperature overnight normally happens just after sunrise, as the suns rays stir up that cold air and send it upwards.
Nature has some fantastic ways to guard against frost. Some plants can produce their own anti-freeze made from amino acids and sugars within the cell walls, while other trees in extremely cold environments like the arctic circle will actually move the water away from the plant cells during the coldest months, where the water can freeze without causing damage.
Composting Checks and Balancesfrom the April newsletter
You'll get out what you put in, and the more astute and observant you are the more likely you will produce great compost. Diligent checking of temperature with a gardeners thermometer while keeping a dairy is your best bet, but for most people, checking your pile often will be enough, especially over the first few days to get things going. You want the temperature to be at 50-60 degrees and if your pile smells bad after a few days, you have probably added too much nitrogen. Add a good dose of carbon and remix the pile, and check again a few days later.If you don't have a thermometer, you can stick your hand in, noting that the pile should be quite hot. If it is not heating up, you might need to add more nitrogen or more water. Observation is key and your growing knowledge over a few cycles will hone your skills.
Brown Rotfrom the March newsletter
The lack of rain before January for most of New Zealand followed by high humidity has been hard for our fruit trees. Unfortunately all of our fruit trees succumbed to brown/fungal rot or fruit just fell off the tree due to stress and lack of water. If a hot, humid summer looks to be on the cards, the only weapon we have to combat these diseases is by trying to increase air flow - by opening up the canopy and making sure your trees aren't crowding each other. We'll be caring for our trees so they can bounce back for next season.