What Is The Optimal Sowing Depth For Common Crop Seeds

The optimal sowing depth is crucial: plant a seed too deep, and it may run out of energy before reaching the surface; plant it too shallow, and it may dry out or be eaten by birds.

The General Rule of Thumb

A reliable guide is to plant a seed to a depth of 2 to 3 times its diameter (or width). This means large seeds go deeper, and small seeds stay near the surface.

Optimal Sowing Depths for Common Crops:

• Very Small Seeds (e.g., Lettuce, Carrots, Spinach, Radish):
  Depth: 1/8 to 1/4 inch.
  These seeds have very little energy stored. They should be barely covered with soil. Some lettuce seeds even need light to germinate and are just pressed firmly onto the soil surface and kept moist.
• Medium Seeds (e.g., Beets, Swiss Chard, Tomatoes, Peppers):
  Depth: 1/4 to 1/2 inch.
  These have enough energy to push through a small amount of soil.
• Large Seeds (e.g., Beans, Peas, Corn, Squash, Cucumbers):
  Depth: 1 to 2 inches.
  These large seeds have substantial energy reserves and must be planted deeper to ensure they are anchored and stay in contact with moist soil.

Always check the seed packet for specific instructions, as some seeds have unique requirements.