hey, this is my first post on this forum, hows it going?
I am here to ask advice on a idea I had recently. I have a 40 acre property in NSW, Australia, in a temperate to sub-tropical climate. I was thinking of planting some trees and I have a few things to take into account:
the area I will be planting on is a hill, and there is occasional light frost in winter, with the temperature on rare occasions going as low as -1 degrees celsius.
I had an idea to dig into the hill, making circles as large as the drip-line of the trees at maturity, and digging these maybe half a metre down, so i have flat circles cut into the side of the hill. I will line the circles with bricks made of stones that absorb a lot of heat and plant the tree in the middle surrounded by companion plants like comfrey and pinto peanut etc.
The idea behind this is to trap heat with the stones and shelter the plants from frost, as well as trapping water in a kind of 'well', and also making it easier to harvest fruit as the tree will be planted lower down .
Maybe a little more info - or maybe I missed something. On the face of it, what's the problem? Most areas have a selection trees of some sort that will grow naturally in the existing conditions. As I understand it, a little frost only matters to citrus farmers and then only in terms of reducing the yield that particular year. Are you planting citrus trees?
sounds like a lot of labor. I fear your stones will be somewhat shaded rather than fully exposed and more importantly, that your dug out will trap frost as it descends the hill.
An alternative that springs to mind is to cut on-contour swales into the hill, with the trees and heatsink stones on the downhill side of the swale's berm.
The benefits I envisage are better and more complete water absorbtion, more heat in the stones from increased exposure, and zero chance of frost trap around the trees - frost which overflows the swale will accelerate past the trees due to the increased downward slope of the berm.
Digging these circles around your trees sounds like extra work when there could be an easier route. I like your train of thought though!
The best way to protect your trees from frost is by having a enclosed canopy. The frost will roll over the top of the trees down the hill. If you wanted to put in swales to harvest water, the canopy would prevent any frost traps.
What zone are you in? How cold are your frosts? How many consecutive and non-consecutive days does it frost for? Does it frost during the day or at night? How many days/ hours do the frost last for. What trees are you trying to grow?
I am in a subtropical environment that has slight winter frosts too. The worst frost we have had in a while was for 7 nights and it got down to 27. We had several frosts that year (two winters ago) The days warmed up to 50.
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