Georgics 2.288–297

288Perhaps you may also ask what depth the trenches should have. 289I would dare to entrust the vine even to a shallow furrow. 290Trees are fixed deeper and far into the earth, the durmast oak above all, which stretches its root as far towards Tartarus as its crown towards the airs of heaven. 293So neither winters nor blasts nor rains uproot it; 294it stays unmoved, and outlasts many generations of descendants, rolling through many ages of men as it endures. 296Then, spreading wide its strong branches and arms this way and that, it stands in the middle and itself upholds a huge shade.