In the Nizhny Novgorod region, planting of garlic before winter is usually carried out in early October before Pokrov. At this time, the air temperature ranges from +5 to +10 degrees, the earth temperature at a depth of 10 cm = 5 degrees.
For planting, I made a small device: I drilled holes with a diameter of 20 mm at a distance of 100 mm from each other in a board 1.2 m long and 15 cm wide. Through these holes, pits are made in the ground with a stick corresponding to the holes with a limiter from the bottom of the board by 8-10 cm. Works best if the ground is slightly damp. The pits in the ground are even and at the same distance from each other both in a row and between rows. I have been using it for many years without bending over the garden.