Photo by Carey Dougan.

Soil testing is one of those things that all gardeners really should do—both to figure out how to treat and make the most of their dirt and also to check for things like, oh, arsenic and lead levels.

For the second year in a row, the University of the District of Columbia is offering free soil testing. Gardeners have through June 26 to fill out this application form to get information about the testing service, which will examine environmental trace metals (including lead, arsenic, cadmium and copper), pH, nitrate, phosphate, and essential elements in the soil samples.

Concerns about lead levels, in particular, have grown in recent years as urban gardening has taken off. Plots near buildings that were built before 1978 or busy roadways are particularly at risk for lead contamination, but any soil in a city could potentially be tainted.

The free tests will be done at UDC’s College of Agriculture, Urban Sustainability and Environmental Sciences, one of the only urban land-grant universities in the country. Then you can enjoy those homegrown tomatoes with some peace of mind.