From ancient times, gardeners have decided when to plant using the cycles of the moon and astrological signs. Because the moon's gravitational pull affects the oceans' tides, it's believed that the pull also affects fluids inside plants. Astrological signs are linked to the elements of earth, fire, air and water. If you want to plant a good crop of below-ground vegetables, wait for a day after the full moon and that corresponds to an earth sign.
To use signs of the zodiac, wait for days that are in specific water or earth signs. Each sign appears at least once a month and lasts two or three days. Consult a Farmers' Almanac for monthly updates on the signs. When the day is in the sign of Aquarius or Sagittarius, plant onions or garlic. Taurus and Capricorn are earth signs and particularly favorable for root crops and potatoes. Libra, although an air sign, favors root crops. Cancer, Scorpio and Pisces are water signs, suitable for all planting. Do not plant below-ground vegetables when the day is in Aries, Gemini, Leo or Virgo.
Below-ground vegetables should be planted between the full moon and the last quarter, because this period favors root growth. The waning moon has a high gravitational pull, which creates more moisture in the soil, while the decreasing moonlight makes plants focus on energizing their roots. Do not plant during the fourth quarter--this is a resting period for all plants.
Change of Phase
Never sow, plant or take cuttings from the 12 hours before through the 12 hours after the exact day of a moon phase change. Work on preparing your beds, turning compost heaps or applying mulch.