Where to test your soil

A good soil test costs less than one bag of the wrong fertiliser. Here is where to send it, what to ask for, and how to get the results back into a plan.

Before you post anything

The lab only tells you what was in the bag. Sample properly: 15 cores to 150 mm in a zigzag across the block, mixed in a clean bucket, about 500 g bagged and labelled. Skip gateways, fence lines, troughs and the spot where the last fertiliser heap sat. For pots and beds of living soil, take 10 cores at mid-depth across the whole area.

Full sampling instructions Watch the 15-second sampling clip

Option 1: Hill Laboratories, Hamilton (New Zealand)

The quickest route for New Zealand growers. Results in about a week, no customs, and our Market garden soil planner reads the Hill PDF directly and turns it into an amendment plan.

  • What to order: the Basic Soil profile (pH, Olsen P, K, Ca, Mg, Na, CEC and base saturation). For vegetables and market gardens add the Sulphur profile and Potentially Available Nitrogen. Ask for Mehlich 3 if you want trace elements on the same report.
  • Form: Hill Labs soil and plant analysis request form (PDF). One line per sample; the sample name on the bag must match the form.
  • Post to: Hill Laboratories, Sample Reception, 28 Duke Street, Frankton, Hamilton 3204. Courier is best; samples can go wet or dry.
  • Contact: 0508 HILL LAB (0508 44 555 22), mail@hill-labs.co.nz, hill-labs.co.nz.
  • Compost or growing media rather than soil? Use the compost and media request form instead; the planner reads those certificates too.

Option 2: Logan Labs, Ohio (send it yourself)

Logan Labs is the test we build our own recipes on: the Standard Soil Test with Mehlich 3 extraction, base saturation and the full trace element panel in one report, for about US$27 a sample. We do not forward samples, but sending your own is simple once you have the permit label.

  • 1. Get the permit label first. Soil cannot enter the United States without a USDA APHIS soil permit sticker on the box. Logan Labs holds the permit and supplies the sticker: email office@loganlabs.com or call +1 937 842 6100 and ask for a soil import permit label. One label per box, and each label can only be used once. A parcel without it is destroyed at the border.
  • 2. Fill in the worksheet. Download the submission worksheet from loganlabs.com/send-a-sample. For garden soil order the Standard Test; for living soil, pots or soilless media order the Complete Soil Package (Standard plus saturated paste and available nitrate and ammonium). Write your email on the worksheet, as results come back by email.
  • 3. Pack it. At least 2 cups (about 500 g) of dry soil per sample in a sturdy, labelled bag, folded and sealed inside a zip lock bag. Pack the bags firmly in a plastic lined box with newspaper so nothing shifts, put the worksheet in the box and the APHIS sticker on the outside. Keep the whole parcel under 1.39 kg of soil.
  • 4. Post it. Logan Labs, 620 North Main Street, Lakeview, OH 43331, USA. Use a tracked international courier and declare it as "soil sample for laboratory analysis, no commercial value". Logan invoices you by email once the samples arrive and reports come back 3 to 5 business days after that.

What to do with the result

  • Hill Labs report: upload the PDF to the Market garden soil planner and it fills itself in.
  • Logan Labs report: our calculators do not read Logan reports. Order a soil prescription, $80, send us the report and your crop list, and we write the amendment plan for you within five working days.
  • Not sure what you are looking at? The same prescription covers any lab's report; reading them is most of what we do.

Test at the same depth, in the same month, every year. The trend is worth more than any single number.