Tricia shows you how to take a good soil sample to send off for analysis.
Get to Know Your Soil: A Guide to Soil Testing
Understanding your soil's health is key to growing a thriving garden. Testing your soil can save you money on unnecessary amendments and ensure your plants get the nutrients they need. Here’s how to take a soil sample and why it’s worth the effort.
Why Test Your Soil?
A soil test can reveal deficiencies in essential nutrients like nitrogen for vegetative growth, phosphorus for fruiting and root development, potassium for disease resistance, and calcium for sturdy cell walls. It also provides insights into your soil’s pH level. Sometimes, the best news is finding out your soil is already healthy!
Tools You’ll Need
- Trowel: Use a clean, cast aluminum trowel with measurements. Avoid tools made from brass, soft steel, or your hands to prevent contamination.
- Plastic Bucket: Gather samples in a clean plastic bucket; avoid using galvanized steel or rubber buckets, which can alter results.
Collecting Soil Samples
- Multiple Beds: Take separate samples for each raised bed or distinct garden area, especially if different crops grew there previously.
- Sub-Samples: Gather about 12 sub-samples in a zigzag pattern for a composite sample of each area. For non-raised beds, space your sampling points 5–10 feet apart.
- Depth: For vegetable gardens, dig 6 inches deep, or as deep as you plan to cultivate.
Preparing Your Sample
- Remove debris like roots and stones from the soil.
- If the soil is wet, spread it on a newspaper in a well-ventilated, shaded area to dry. Never use heat to dry your soil.
- Collect about a pound of soil in a plastic bag and send it to a testing lab.
Test Results and Next Steps
Most gardeners need a basic soil test covering nitrogen, phosphorus, potassium, pH, and organic matter. New gardens or untested soil may benefit from a micronutrient test, analyzing elements like zinc, copper, and manganese. Once your results arrive, you’ll also receive recommendations for organic fertilizers to address any deficiencies.
Get to know your soil and set your garden up for success. Grow Organic for Life!
For more information, see our article on How to Test Your Soil at Home.
