This March calendar page from The Hours of Henry VIII is a fairly typical March scene in terms of the labors of March depicted in a book of hours. Workers are pruning the grape vines. You’ll notice that it’s early enough that the vines are still without leaves. While it’s possible to prune vines later, it’s not a good idea as the vines will often bleed sap, which isn’t conducive to producing happy grapes. It’s also much easier to tie the vines to a supporting frame or arbor when they aren’t in full leaf but have leaf-buds. As the workers prune grape vines, they tie them to the arbor so that as the vines grow and sprout leaves and then grapes, the vines will have support.
You can see the pruning tool being used in the detail to the left. This is a Medieval billhook, a sort of all purpose agricultural tool with a double-edged curved blade and sometimes a short spike at the crown and a small hatchet-like blade on the outside edge. It’s perfect for a task like vine-pruning because you can slice the thinner vines with the curved blade and whack off those that are a bit thicker with the small hatchet. This is the same tool known as the falx or falx vinatoria used by the Romans to culivate vines. A modern vine pruning knife, while it often folds up and fits in a pocket, retains that curved cutting blade.
On the left the worker standing on the bench has a shock of fibers he’s using to bind the vines to the supporting framework of the arbor. On the ground, near the middle of the image in the front is a small flat-sided cask with a spout; this contained something for the workers to drink, possibly water, or water with vinegar and honey, and probably not wine.
In the bottom center of the calendar page is the astrological symbol for Aries, the Ram. The margins contain images associated with feast days in March; St. Gregory for March 12, and the Annunciation on March 25 at the bottom right.