Soil sampling planner
Tell us what you grow and how many areas you have. We work out how many bags, how many cores and how deep to dig.
Your sampling plan
- 1 separate sample bag (one per area).
- Each bag: 10–15 cores taken in a zigzag across the area, mixed in a clean plastic bucket.
- Depth: 3 to 4 inches. Scrape off thatch, mulch and debris first.
- Send about 1 to 2 cups (roughly a pint) of the mixed soil per bag, air-dried if your lab asks.
These are typical Cooperative Extension instructions. Your state lab’s form wins if it differs. Avoid sampling right after fertilizing or liming.
Why sampling matters more than the lab
A soil test can only describe the soil you send. Most bad results come from too few cores, the wrong depth, or mixing areas that are managed differently. Land-grant university labs ask for a composite sample: many small cores from one area, mixed together, so the result reflects the whole lawn or bed rather than one spot.
Keep areas separate when they get different fertilizer, lime, or crops, or when the soil clearly differs (low wet spots, old garden sites, areas near the house where construction fill or old paint may be). Label each bag and record the crop you plan to grow, since recommendations depend on it.
Next, find your state’s lab and how to submit on our state pages, then read how to read your report.