Do a percolation test for drainage

Dig a hole 12 inches deep and 12 inches wide. Fill it completely with water and let it drain to saturate the surrounding soil. Immediately refill, measure the water depth with a ruler, then measure again after 15 minutes. Multiply the drop by 4 to get your drainage rate in inches per hour.

Why It Works

The first fill saturates the soil so the second measurement reflects true drainage, not dry soil absorption. Iowa State University Extension teaches this as the standard field drainage test. Results directly tell you whether your soil drains too slowly (waterlogging risk), too fast (drought risk), or at an ideal rate.

Tips

• Less than 1 inch/hour: Poor drainage — add organic matter (never sand to clay), install raised beds, or choose water-tolerant plants
• 1-3 inches/hour: Ideal for most garden plants
• More than 4 inches/hour: Excessive drainage — add organic matter to improve water retention
• Test in multiple locations since drainage varies across a yard
• Results can vary by season and water table level — test when soil conditions are typical