How to take a soil sample

Taking a soil sample, in a few easy steps

Start by cleaning a shovel with water only.

1) Scrape away the top layer of organic material until you see mineral soil. This is usually less than 2” down.

Scrape off organic matter

2) Dig a hole 6” (15 cm) deep. This is the default depth for a soil sample, and is where most of the roots of flowers and vegetables live.  If you are in a no-till situation, like an orchard, dig a 3” (8 cm) deep hole and be sure to let your testing lab know the depth of the soil sample.

3) Using the shovel, slice a thin layer of soil from the side of the hole, from the top of the hole to the bottom of the hole.

Dig a hole

4) Put an even section of this soil slice into a clean glass bowl. Stir it up with a clean stainless steel spoon.  Avoid touching the soil with your fingers.

Put it in a bowl

  • Repeat steps 1-4 until you have a representative sampling. This is 6 to 15 holes, depending on the size of the area.
  • For a 100 square foot garden bed use 3 or 4 holes.

Avoid atypical areas. This means avoid both the best and worst areas.

5) Take 2 cups (500 mL) of this mixture, and put it in a plastic bag. If it is really, really wet, you can let it air dry, but don’t put it in the oven. Label the bag with your name, your email address and the name of the sample (for example, “Veg Garden”).

Load up the bag

6) Do a fizz test.

  • Put an ounce of dry soil in a clean, dry bowl.
  • Add a tablespoon of white vinegar (5% acetic acid).
  • Listen carefully.

The amount of fizz is roughly proportional to the amount of carbonate in the soil. If you have to listen closely to hear it, it is weak. If you can see lots of bubbles, it is strong. Medium is in between.
If you have fizzy soil, you should get an AA8.2 soil test rather than the standard.

7) Print and fill out the worksheet here.  Pack a cardboard box with your samples, the printed worksheet and a check made payable to Logan Labs (see this page for amount). Make sure any extra room in the box is filled with packing material so the samples cannot move. USPS Priority Flat Rate boxes are usually the least expensive to ship, however other carriers such as FedEx or UPS may be used.

8) If sending samples from outside the continental U.S., Enclose Soil Permits (Soil Permits).

9) Ship the box to Logan Labs, 620 N Main St, Lakeview, OH 43331. If sending by US mail, you must drop the box off at the post office counter – don’t put it in a mailbox. Alternatively your mail carrier may pick up the box; see here.

10) Subscribe to OrganiCalc.  Your test results will be emailed to you within a week after your sample is received at Logan Labs.  Enter the results into OrganiCalc for a list of recommended amendments.

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