Your backyard garden is only as healthy as the soil it grows in. Here’s how to test your land for lead, other heavy metals, and nutrients, with the help of our friends at Grow Pittsburgh — who joined us on the City Cast Pittsburgh podcast for a guide to backyard gardening.
Using clean, non-galvanized tools, gather a dozen soil samplings — about 4 to 8 inches below the soil’s surface — across your garden site. (The zinc in galvanized tools can affect your sample.)
Once you have the samples, place them in a bucket or bag and mix them together; then, separate them into two so you have an extra sample in case you need to re-test later.
Remove debris and clumps from one half, and spread it out on clean paper to dry; this could take a few days.
Once dry, mix it again, and use a sieve to filter out any rocks or plants. Place a cup of that soil in a zip-lock bag with your name, address, and sample ID labeled on the outside.
Grow Pittsburgh recommends sending your sample to UMass Amherst’s Soil and Plant Testing Lab. Their test kit costs $15 and includes results for pH, basic nutrients, heavy metals, and aluminum. They’ll also give you suggestions on how to adjust the nutrient and pH levels through organic methods. Penn State Agriculture Analytics Laboratory also offers testing.
Tip: Keep an eye out for the Allegheny County Conservation District’s free soil screenings throughout the year.
Make sure to test the soil before expanding your garden to a new area, and test all plots every few years to keep up with their nutrient levels.