Soil and Plant Laboratory Inc.
organic, inorganic and wet chemistry laboratory

Typical Sampling Depths

  • Turf and annual or ground cover beds = 1-6 inches
  • Shrubs, Rose beds, vegetable or shallow rooted field crops = 1-12 inches
  • Deeprooted field crops = 1-18 inches
  • Trees = 6-18inches
  • Very deeprooted trees = 24-36 inches
  • Raised beds, pots, miscellaneous planters = full depth

Soil Sampling Instructions

The value of an analysis and its interpretation depends upon examination of a representative sample. Samples may be taken for preplant information, growing on information, or troubleshooting. The sample should represent the root zone, although special problems may require samples from other zones. Contact one of our consultants when in doubt.

A representative sample consists of a composite of several subsamples taken from the area under investigation. Equipment for sample may consist of spade and bucket, an auger or a soil sampling tube. Place the sample in a plastic bag. Written information including your name, address, phone and fax numbers, sample description, analysis desired, purpose of the analysis and purchase order or other authorization should be included with the sample shipment but not in the same bag as the soil.

Sample quantity must be sufficient for the appropriate analysis selected. Accuracy requires adequate sample size. Most analyses can be conducted on a one-pint sample of soil, with the exceptions of the A04, A05, A09 and A91 (one-quart), A06 (one-gallon) and M04 (three gallons).

In all cases, discard the surface inch of soil to avoid including debris which is not part of the actual rootzone. For drip irrigation, take the sample close to the emitter and discard the upper two inches.

 Serving the horticultural industry since 1946!

Soil and Plant Laboratory, Inc.
4741 East Hunter Ave. · Suite A · Anaheim, CA 92807
(714) 282-8777 · Fax (714) 282-8575