Planting by the moon’s cycles is an age old folklore. The farmers almanac gives instructions. Why would it make a difference? People understand that the moon’s gravitational forces have an effect on the rise and fall of the tides. In the same way, the moon’s gravitational cycle has a subtle effect on the way moisture in the soil rises and falls. The moon’s light also affects the growth of plants.
So the old folklore is that to plant by the moon, one needs to plant above ground crops during the waxing phase of the moon. This is the time from the new moon until the full moon and during this time the earth is fertile and wet. Above ground crops include tomatoes, peppers, peas, cabbage, and greens.
When the moon is waning, the light from the moon is decreasing and the earth is drier. This is the time from the full moon until the new moon and this is the best time to plant below ground crops. This includes onions, potatoes, carrots, and radishes.