Urban Gardening Alert: Protect Your Harvest from Toxic Lead

The dog days of summer bring a bounty of homegrown produce from the postage-stamp garden plots that dot the urban landscape. There's a special joy in sitting down to a summer supper featuring sweet tomatoes, bright basil, and roasted beets you've nurtured yourself. But before you feast, it's critical to understand that urban gardens may harbor toxic levels of lead—posing risks of brain and nervous system damage in children and neurological and gastrointestinal problems in adults.

How Lead Enters Urban Gardens

Lead contaminates urban gardens primarily through two pathways:

• Lead-based paint chips from homes and buildings constructed before 1950. Research shows the highest lead concentrations cluster around building foundations.
• Auto emissions and lead dust that settle on vegetation, especially within a few feet of busy roads.

Practical Steps for Safer Urban Gardening

While professional soil testing and remediation are ideal, they're often cost-prohibitive. If you suspect lead in your soil, you can still grow food safely by following these strategies:

1. Choose Your Garden Location Wisely

Site your garden as far from buildings and busy roads as possible. This reduces both soil contamination from paint chips and lead dust settling on crops.

2. Select Fruiting Crops That Resist Lead Uptake

Tomatoes, squash, okra, eggplant, and corn tend not to accumulate lead even in contaminated soil, making them safer choices.

3. Use Raised Beds for Leafy Greens and Root Vegetables

Lead concentrates in plant leaves—the parts you eat in herbs and lettuces—and even thorough washing may not remove all contaminated soil from root vegetables. Build raised beds lined with landscaping fabric and fill them with fresh, organic soil for these crops.

4. Explore Phytoremediation

If you have a questionable yard space, consider growing "hyperaccumulator" plants like Indian mustard, spinach, sunflowers, or blue fescue for one or two seasons to extract lead from the soil. Remove and dispose of these plants safely (not in compost) at season's end.

5. Wash and Peel Root Vegetables Thoroughly

If you're already growing carrots, beets, or potatoes in suspect soil, scrub them vigorously and peel before eating. Consider keeping these crops off young children's plates.

These precautions are prudent for all urban gardeners. In dense city environments, it's impossible to control every potential lead source, but these steps will help you savor your summer harvest with confidence in its safety.