The dirt on dirt: a practical guide for the city farmer on what to do when you turn up a toxic plot. We sift through the soil pros and cons.

The line of first defence

Compost remediation (adding a layer of compost to contaminated soil)

Pros Cheap, quick. 

Cons The compost only provides a layer of protection.

Eco risks The contaminants remain.

Digging Deep

Excavation (aka removing the offending dirt)

Pros Out of sight, out of mind, right?

Cons You may need to call in the heavy machinery. Getting rid of it at a special landfill isn’t cheap – you’re looking at five Gs.

Eco risks Plants can suck up contaminants if you don’t dig deep enough.

If you’re into plants

Phytoremediation (using greenery to extract contaminants)

Pros It’s nature’s way – and inexpensive, less than a thou.

Cons Takes forever. 

Eco risks Plants used for extraction must be disposed of in special landfills.

If you live on or near old industrial land

Soil washing (sending the stuff away for treatment)

Pros Safe bet your tomatoes won’t be laden with heavy metals.

Cons Costs a ton, up to five Gs. 

Eco risks Disposing of the contaminants removed from the soil can be a real mess.

The best option for the earth

Microbial remediation (now we’re talking – using microbes to eat up toxins)

Pros Effective in cleaning soil of hydrocarbons, pesticides and PCBs. 

Cons Not so much for heavy metals.

Eco risks A possibility of increasing the toxicity of certain metals. 

If you believe mushrooms can save the world 

Fungal remediation

Pros Powerful. Organic. Capable of mitigating the harmful effects of depleted uranium. (No kidding.)

Cons Still in the development stages.

Eco risks Adverse health effects from fungal contamination.

If heavy metal’s not your thing

• Planters

• Hydroponics (the dirt-free alternative)

• Try a cleaner plot.