Purdue Extension - Allen County offers soil testing services to analyze the nutrient levels of your soils. We also help you understand your results and find solutions. Soil testing fees are $20 per sample. Here is some helpful information to make sure you get most accurate results for your money.
Where and When to Sample
Keep samples from different areas separate. Areas treated different or with different characteristics will have different soil profiles. Examples of areas which should be treated different include
- Front yard vs back yard
- lawn vs landscape
- dry areas vs wet areas
It is best to take samples in spring or fall before applying fertilizer. Give yourself enough time to get results back and determine which products to buy for your soil.
- Gather supplies
- soil probe or spade
- plastic bucket (metal buckets may transfer trace minerals to the soil)
- bag(s) for soil
- Clear surface of debris
- Take at least 5 random samples from the area
- generally moving around the area in M or Z shapes work well to cover the space
- samples should be 3" deep for lawns, 6-8" deep for gardens/crops/shrubs, and 8-12" deep for trees
- Place soil in bucket
- Mix soil and fill bag (2 cups of soil per sample)
Reference the new Purdue Extension publication HO-71-W "Collecting Soil Samples For Testing" for more detailed procedures
Ensure you have 2 cups of soil
Sample every 2-3 years at the same time of year
Allow time for samples to be processed before fertilizer needs to be applied. This can take up to 2 weeks but is often much shorter.
Contact James Wolff (Agriculture and Natural Resources Educator) or Terri Theisen (Horticulture and Urban Agriculture Educator) for more information.