No more plastic greenhouses or tunnels needed : grow your own live greenhouse (a green teepee or a tunnel) with branches of the drought-tolerant Navajo willow, also called globe willow or Chinese willow (Salix matsudana). One can grow these willows with a minimum of water in the drylands, even in the desert.
Such a live greenhouse offers remarkable advantages : natural shade and higher air humidity inside because of the transpiration by the leaves.
In drylands or deserts people can easily grow plants, e.g. young fruit trees and vegetables, inside such a greenhouse, which can also offer shelter against the sun heat.
Outgrowing branches of the willow can easily be pruned to construct progressively new greenhouses. A very interesting way to combat drought and desertification.