Central and Western Europe have been farmed for thousands of years by that point. Farming in Southern France/Iberia was already well established around 7000 years BP (before present). By the time of Romans, the hunter-gatherer's lifestyle was wholly displaced from the area, with only minuscule fraction of resident population engaging in it, at best.

See e.g. First Farmers of Europe, https://www.amazon.com/First-Farmers-Europe-Evolutionary-Per...