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” 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” 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 1 cup 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.

Load up the bag

6) Pack your box with the baggie of soil and the filled out Worksheet from your lab.    If there is any space left over, add packing material so that the soil cannot move during shipment. Be sure to note the sample depth on the form if it is different than 6 inches.

7) You can drop the box off inside the post office at the counter or you can have them pick it up by filling out an online form here: https://tools.usps.com/go/ScheduleAPickupAction!input.action  Don’t drop it in a mailbox!  “Priority Mail envelopes or packages weighing 13 ounces or over with adhesive postage stamps cannot be deposited at unattended receptacles such as collection boxes and lobby drops. These mail pieces must be taken to your nearest USPS retail unit or may be given to your carrier if you are a known customer to him/her and have included your return address.”

 
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