To plant dahlia tubers, dig a hole about 4 to 6 inches (10 to 15 cm) deep. Place the tuber horizontally on its side with the growing eye (or "eye") facing up, then cover it with soil

. Some sources mention planting the tubers just under the soil surface or lightly covering the buds, but generally 4 to 6 inches deep is recommended to allow for proper growth and protection

. Additional tips include spacing the tubers about 12 to 18 inches (30 to 45 cm) apart to allow airflow and room for growth

, and planting after the last frost when the soil temperature is at least 60°F (15°C)

. Avoid watering immediately after planting unless the soil is very dry, and wait until sprouts appear before watering regularly

. In summary:

• Dig a hole 4 to 6 inches deep
• Place tuber on its side with the eye facing up
• Cover with soil to about 4-6 inches depth
• Space tubers 12-18 inches apart
• Plant after frost risk has passed and soil is warm

This depth ensures the tuber is protected but not buried too deeply, which could delay sprouting