Soil
Treat the soil, not the symptoms™.
Your soil has a bank account. We read what it owns and what your roots can spend today.
Logan Labs runs two tests on the same sample: saturated paste, which reads the nutrients dissolved in the soil water, and ammonium acetate exchange, which reads the mineral reserve. One test alone can send you buying something the soil already holds. We bring both together into a score, a story and a plan that says what to add, what to leave alone and why.
Start with the unfavorable findings. If potassium is truly short, feed it. If phosphorus is already piled high, stop adding it. Let the next round of numbers, not wishful thinking, tell you whether the work landed.
$200 list price
The soil test costs $200 at list price or $100 for members. A printed report is included; no membership includes a free test.
A sample garden's mineral balance
Calcium 58% · magnesium 19% · potassium 2.8% · sodium 1.2%. Sample score: 23/100. Read the whole report.
Four lenses, one read
The two Logan tests are standard. Biology and water are separate, optional reads when there are real measurements; the public sample shows only the two Logan tests.
Saturated paste
A saturated paste is a lab test that squeezes the water out of a moistened soil sample and measures what has dissolved in it. That is the mineral mix roots can actually drink this week. If a nutrient is short here but plentiful in reserve, another bag of fertilizer may not be the answer; the soil life may need help unlocking what is already there.
Ammonium acetate mineral
The ammonium acetate test measures the nutrients the soil holds on its particles, its mineral bank. It also tells us what share of the holding sites carry calcium, magnesium, potassium and sodium. William Albrecht taught that this balance matters: too much of one nutrient can keep a plant from reaching another.
Biology, when tested
Optional microscopy or a Haney/Regen add on tells us what is living, what is cycling and what is still sitting in the bank. A good mineral read without a working soil food web can leave nutrients stranded. Elaine Ingham showed that the organisms eating each other release nutrients plants can use.
Water, when tested
Your irrigation water brings minerals to the bed every time you turn on the tap. Check what it contains before setting fertilizer rates, or you may add more of something already in excess. For extract, free chlorine needs to read zero at the hose end: chlorine kills the living organisms you are trying to put into the soil.
Same spots. Same depth.
Take small cores from the same spots every round, at 0–6 or 0–8 inches. Pick one depth and keep it. Mix the cores into one clean composite sample, remove roots and stones, then send it to Logan Labs. Soil changes with depth and across a bed; sampling somewhere else next time can make your numbers move even when nothing in the ground changed. Never compare unlike extraction methods, because they measure different pools of nutrients.
What you get
A report that starts with the hard truths, then gives you the working parts, the plan and the lab numbers behind it. Each recommendation says what to do, why those numbers matter, what happens if you ignore the finding and what to watch when you test again. Optional biology and water findings only appear when those tests were actually run.
Your reports →