What every urban gardener needs to do before planting

Soil contaminants pose risk to growers
Posted at 6:11 AM, May 30, 2018
and last updated 2018-05-30 07:27:00-04

As urban gardening grows in popularity more and more people are trying their hand at a green thumb. However, those new to urban gardening should be aware of the threats caused by soil with contaminants and the need to test.

“In this situation, ignorance is not bliss,” said Michigan Urban Farm Initiative’s B.J. Franovic. “You should test your soil, you should figure all of that out.”

Franovic stressed the need to test your soil, but also noted it’s not a death sentence if you find high levels of lead or other toxic materials in your soil. The EPA offers similar advice online stating, “the possibility of contamination at a garden site should not keep you from planning an urban garden,” but it does require special attention.

If an area has a history of industrial use, or a home has previously been demolished on the site where an urban garden is planned it’s more likely that issues could be found within the soil. Either way, it’s easy to test soil.

The folks at Michigan Urban Farm Initiative suggest performing the tests yourself — having someone do the testing for you can prove to be inefficient in terms of cost. Luckily, testing is a one-time thing and not something you do annually.

A number of groups offer advice on how to take a soil sample to send to a lab. You can find video examples, here; and instructions, here. MUFI suggests sending samples to the University of Massachusetts Amherst — many local companies utilize the company and because of it’s size and the type of program they run it’s low cost.

What you’re looking for is whether the soil has an unusually high level of contaminants. The EPA lists common sources of contaminants as lead paint from before 1978 (lead), treated lumber (arsenic, chromium, copper), pesticides (lead, arsenic, mercury), etc.

Lead contaminants are getting more attention because of Flint’s ongoing water crisis, but it’s important to note that some lead will be found in soil as it’s naturally occurring. However, if the levels are too high you may need to change your approach — building a raised bed for your garden, or mixing in organic materials to neutralize your soil.

In metro Detroit there is a history of issues with lead levels in the ground in some areas. Recently Collins Park was shutdown and remediation is currently underway after high levels of lead were found as playground equipment was being prepared to be installed. If you drive by the property now it’s blocked off by an orange fence, and several layers of dirt have been removed.

“Basically, you should get soil tested — that’s the easiest way to figure everything out, and it’s a good caution to have,” said Franovic. “If you have a land plot that was previously industrial you should probably expect some problems and complications with that, but if it was residential you’ll probably be more toward the safe side. Either way you should get that tested and figured out.”

If you’d like to learn more about EPA’s suggestions for best urban gardening practices, and what techniques are helpful when contaminants are present you can visit their help guide.