A very simple, yet elegant, garden. The castle's donjon (keep) is visible just behind.
In many formal French gardens, potted plants, shrubs (like these), and trees are taken indoors for the coldest part of winter. The bigger châteaux (like the Louvre or Versailles) had special buildings for over-wintering citrus trees and other warm-climate plants like palms. The buildings are called orangeries and many are still used to shelter plants during the cold weather. One famous orangerie, in the Tuileries gardens outside the Louvre in Paris, was transformed into an art museum in the early twentieth century. If Villandry has an orangerie, I did not see it.