At least as common as it is a bit too dry forest garden (is previous post) it is that the water table is too high for trees and shrubs will thrive properly. But what is too loud really? The rule of thumb is that the bushes would like to have 60 cm down to the highest ground water and trees want most 1 m or more. With the highest groundwater level refers to the level prevailing in the spring, after the spring thaw and snowmelt. The reason that trees and shrubs do not want it too wet feet is that their roots need oxygen to function. Is the soil saturated with water, it means that every pore is filled with water and the roots suffocate. The problem of high water of the images illustrated below. After the winter, the water table high and the tree has its roots only in the topsoil. In the spring and early summer decreases because the water level gradually, but the roots do not grow so fast that they would have time to penetrate the soil volume which is now available. Instead, all the roots concentrated in the driest part of the soil profile, and there is no chance for the tree to access the water present in the deeper layers of soil, with drought stress, poor growth and even poor overwintering ability resulting. The result is even competition for water between plants increases, like it happens in dry slopes.
This event occurs mainly on flat land in areas of typical cases 3 in a previous posts. As I mentioned, there have been in traditional agriculture solved the problem by draining the land to permanently lower the water table. Then the tree from the beginning to have a larger volume of soil to grow through, with the result that the plants can be planted more densely, and will generally be more robust. It is not always that you will be able to drain the. There are interests of both upstream and downstream, if you are in agricultural district that need to be considered. Here, in the putt Myra forest garden is a culvert that is placed a few inches too high, which means we can not drain the water that creates problems for us in the spring. Can not you ditch the, you need to instead raise the orchard. We have tested different variations on this.
Our favorite solution is to dig deep pits and use the excavated material for building raised garden hills. The pits we have dug in strategic places (mainly different inflexion) and it was not many hours (actually) before the pits turned into ponds.
Another solution we have used a lot is that we dig individual raised litters each tree. Earth takes us from the immediate area (within a few meters) and thus creates a more varied topography with different microclimates and more habitat for various livestock.
The same principle is behind what one might call the opposite trenches. Then select the line where you want to plant trees and shrubs. The lines can be straight or curved organic as you want. Then you take the soil contained between the lines and build long raised beds with the. A suitable width of these is 2 to 3 m. This is best done using a small excavator in the case of more than a few meters.
In other words, it is quite easy to get around the problem with a little bit of high ground, although it always means more or less digging. Another thing that requires excavating work is construction of dams – more on that in the next post.