A few quotes from the Rabbi on 'Redemption of Israel'
in which he praises the planting of trees in the Land of Israel
People all know, and furthermore, it is a dear and lofty divine commandment, for the sake of goodness and glory, to build and to plant, even a single house, in the Land of Israel, and most certainly to build synagogues and study houses.
Land of Israel sermon, in Peter Rehem, p.8, Jerusalem, 1961