How to Do a Soil Percolation Test

The November/December issue of Northern Gardener includes Nancy Rose’s article called “A Tale of Two Soils.” Many Minnesotans know Nancy from her years as a horticulturist at the University of Minnesota. A few years ago, she moved to Massachusetts. In her article, she talks about the difference soil makes in what you can grow and how you approach gardening.

She recommends gardeners conduct a couple of home soil tests to determine the type of soil they have. Here’s the first test.

Soil Percolation Test

This test will tell you how well your soil drains. Run the test in multiple locations within your yard for comparison.

1. Dig a straight-sided, flat-bottomed hole 12 inches deep.

2. Fill the hole with water and let it drain completely.

3. Fill the hole with water again and place a measuring stick in the hole.

4. Check the water level every hour and write down the levels.

Results: If the water level drops at less than ½ inch per hour, the soil is poorly drained. A rate of 1 to 2 inches an hour means good drainage. More than 3 inches per hour is too fast and will have to be watered too frequently.

Tomorrow: Testing Soil Texture