The quotation comes from Lucretius’s De Rerum Natura (The Nature of Things), V.1369-1377 (50 B.C.E.), where the poet honors those who first cleared the land
for vineyards. William Ellery Leonard’s somewhat loose 1916 translation reads:

And day by day they’d force the woods to move
Still higher up the mountain, and to yield
The place below for tilth, that there they might,
On plains and uplands, have their meadow-plats,
Cisterns and runnels, crops of standing grain,
And happy vineyards, and that all along
O’er hillocks, intervales, and plains might run
The silvery-green belt of olive-trees,
Marking the plotted landscape; even as now
Thou seest so marked with varied loveliness
All the terrain which men adorn and plant
With rows of goodly fruit-trees and hedge round
With thriving shrubberies sown.