Testing Potting Soil Quality

There are no hard and fast rules about how fast good quality potting soil should drain or how much water it should retain.

Here is one way to compare the difference between two products you are considering.

For each one:

1. Both materials to be tested should be moistened to a consistency where, if squeezed by hand, a drop or a few drops of water is squeezed out between fingers. After pre-moistening, keep the potting medium in a plastic bag overnight before testing. This helps insure all of the material is moist.

2. Using identical pots, overfill each one with potting soil; tap each one firmly 3–5 times on a table to eliminate air pockets. Carefully scrape excess material from the surface of each pot, maintaining an even surface at the exact level of the top of the pots.

3. Pour one quart of water over the surface of each pot. The water should filter through in less than a minute.

The pot that empties fastest contains potting material that is more porous. This is typically better for plants.

african violet 2

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