Free Garden Tool
Soil Test Decoder
Enter your soil test results and get a professional-grade interpretation — what each number means, why it matters, and exactly what to buy and apply. Every recommendation sourced from university extension research.
Why Soil Test Numbers Are Confusing
You sent your soil to a lab, got the results, and now you are staring at a page of numbers with no idea what they mean. You are not alone. Soil test reports are notoriously hard to interpret because the numbers depend entirely on which chemical extraction method the lab used.
Different labs may give you different results from the same soil sample depending on their testing procedures. Each method has its own optimum ranges, and the numbers are not directly comparable. This tool matches your lab to the correct ranges automatically.
How This Tool Works
Select Your Lab
Tell us which lab tested your soil. This sets the extraction method and interpretation ranges.
Enter Your Numbers
Type in pH, phosphorus, potassium, and other values exactly as they appear on your report.
Get Your Plan
See what each number means, which nutrients need attention, and specific products and rates to fix them.
Labs We Support
This tool handles three major extraction methods covering virtually every soil testing lab in the United States:
Modified Morgan
UMass, UMaine, UVM, UConn, Cornell, URI
Mehlich-3
UNH, Penn State, Waypoint, A&L, Brookside, Logan
Olsen
Colorado State, UC Davis, Utah State, Montana State
Learn more about our data-driven approach, explore the companion planting guide, or score your garden's biodiversity.
Which lab tested your soil?
This is the most important question. Different labs may give you different results from the same soil sample depending on their testing procedures. Each method has its own optimum ranges, so the numbers are not directly comparable between labs. This tool matches your results to the correct ranges for your lab.
Modified Morgan (Northeast US)
Mehlich-3 (National / Commercial)
Olsen (Western US / Calcareous Soils)
Not sure which method your lab uses? Check your report header or the lab's website. If you used a lab not listed here, pick “Other” for the closest extraction method. When in doubt, contact your lab directly.