Why Test Your Soil?
Many soils across the Piedmont region of North Carolina are naturally acidic and low in essential nutrients like phosphorus or potassium. Adding fertilizer without testing can result in:
- Nutrient Waste: Applying fertilizer that your soil already has in abundance.
- Plant Damage: Over-fertilizing can burn plant roots or hinder growth.
- Environmental Impact: Excess nitrogen and phosphorus runoff can contaminate local waterways and Lake Norman.
- Incorrect pH: If soil pH is too low or too high, plants cannot absorb nutrients, even if fertilizer is present.
How to Take a Soil Sample
A soil test report is only as accurate as the sample submitted. Follow these step-by-step instructions for reliable results:
Gather Supplies:
Clean tools prevent sample contamination.You will need a clean plastic bucket, a stainless steel trowel or soil probe, and official NCDA&CS soil sample boxes (available free at the Iredell County Extension office). Avoid galvanized or brass tools, as they can alter metal readings.
Identify Sampling Areas:
Sample distinct areas separately. Divide your landscape into uniform areas based on plant type or problem spots. Take separate samples for your lawn, vegetable garden, flower beds, and fruit trees. Never mix soil from different areas.
Collect Core Samples:
Mix 8 to 12 cores per sample box. For each area, collect 8 to 12 small cores or slices of soil from random spots.
Lawns:
Sample to a depth of 4 inches.
Gardens & Beds:
Sample to a depth of 6 inches.
Mix and Dry:
Moist soil delays processing at the lab. Combine the cores in your clean plastic bucket and mix thoroughly. Spread the soil out on newspaper to air-dry at room temperature if damp. Do not heat the soil to dry it.
Fill Box and Submit:
Complete the required form. Fill the NCDA&CS soil sample box up to the red fill line. Label the box with a sample ID (e.g., "Lawn Front", "Veg Garden"). Fill out the Soil Sample Information form with your plant code and contact details.
Testing Schedule and Fees
Soil testing is processed by the North Carolina Department of Agriculture & Consumer Services (NCDA&CS) Agronomic Division in Raleigh.
Time of Year Fee per Sample Turnaround
Peak Season (Nov 15 – Mar 31) $4.00 per sample ; 4 to 6 weeks
Non Peak Season (Apr 1 – Nov 14) FREE ; 1 to 2 weeks
Tip: For the fastest results and zero cost, sample your soil during the late spring or summer months before fall lawn renovation or spring garden planting.
Pick Up Your Kit
You can pick up free soil sample boxes and submission forms directly from our office:
- Address: N.C. Cooperative Extension – Iredell County Center
444 Bristol Dr, Statesville, NC 28677 - Office Hours: Monday – Friday, 8:00 AM – 5:00 PM
- Phone: (704) 873-0507
Note: Homeowners are responsible for mailing their completed sample boxes to the NCDA&CS lab in Raleigh (mailing address is printed on the sample form).
How Do I Get My Results?
When complete, your results will be sent to you via email (look for a message from AGRONOMIC LIMS), as well as posted online at the Agronomics Service Division. For help reading the soil test results, refer to this guide or contact your local Extension center.
Need Help Reviewing Your Soil Report?
If you need assistance interpreting your NCDA&CS soil test results or choosing the right fertilizer blend, contact our office or drop by the Plant Clinic (M-W-F, 10am-12pm):
- Contact: Melinda Roberts, Horticulture Agent
- Extension Master Gardener, Plant Clinic
- Phone: (704) 873-0507
- Address: 444 Bristol Dr, Statesville, NC 28677
Helpful Links
Soil Testing for Homeowners
How to Collect Soil SamplesHomeowner Soil Submission Form
Instructions for Submitting Soil Samples
Understanding Your Soil Report
NC Dept of Agriculture Soil Samples
