Seriously sketchy soil. Safe?

[Amandala]

So, we moved in to an apartment with a backyard in March and there was a huge pile of rubble in the sunny corner of the yard. Chunks of concrete, pavers, slates, stones, sticks, bits of metal, you name it. Then they had a patio built and the workers hauled the pile of rubble off. So I want to plant things over there.

Thing is I started digging and I'm coming up with some weird gritty stuff, rusted bottle caps, a rusted keychain, a couple of AA batteries, some piece of some kind of electrical equipment, nails, lots of shards of glass, etc. About 8 inches down to New Jersey clay.

I wonder, is it safe to plant things I am going to eat in this dirt once I add a bunch of organic material to it? Or am I going to need to scoop all this dirt out and buy a bunch of good dirt to fill in with? It does seem like it could be pretty polluted dirt, and I'm afraid any bad stuff in it might go into the plants and then we'd eat it.

Is that how it works? Should I be worried about that? And if so will it be safe if I dig it out and put some good soil in? And if so how deep to be safe?

I'm a n00b.

[lunarlady]

The main thing to worry about is chemical contaminants in the soil. Of the items you've found, only the batteries really give me pause. But it sounds like there could be all sorts of strange things in the soil, and you really don't want to eat those. Yes, your food plants will absorb chemicals from the soil around them.

If it were me, I would go for a raised bed and scratch the digging all together. Just build yourself some nice raised beds, fill with quality soil, and go from there. Much easier than digging out. And if you are going to buy soil anyway, why not? Good for the back too. Good luck!

[sunnysandiegan]

My advice would depend on how long you plan to live there and make use of this space. If short-term (1-2 growing seasons), then I would do container gardening. Make use of any and all containers (food grade or plant grade) you can get your hands on.

If long-term (3+ growing seasons), then I would do a raised bed or container gardening (if you have room to use the containers again) this season while composting directly in that sketchy soil for a full year. Then, the sketchy soil would become good soil and you could use it for future growing seasons.

Personally, I would start adding compost materials (fruit & veggie peels/ends/seeds, used coffee grounds, newspaper, leaves, etc) directly in that sketchy soil right away. After, of course, removing those batteries and any other chemical type items.

Also, is this space a one-time dumping ground area (from a specific project) or is it a common space for people to litter? That would also influence my advice.

[ivymae]

I'd definitely do a raised bed or container garden this year. Call your local extension office though - most state universities will do a soil analysis for a small fee (ours is $30) and tell you if it is safe, as well as what amendments you should do to make it optimum. We recently submitted a sample because we fear there has been lead contamination (old house/paint flakes in the soil) and the turn around time isn't as fast as a private company, but it's a lot cheaper. We built beds this year, and will decide whether to expand the garden in the ground next year, or build more beds.

[mindymom]

I would second the suggestion that you get a soil test. Be sure that your test provider tests for mercury and lead - sometimes these tests are included and sometimes they cost extra or aren't offered.

If there are harmful levels mercury or lead in your soil I would put a barrier material down before planting a raised bed or container garden. Plant roots frequently grow through the drainage holes in the pots that I set on my garden soil and move down into the soil.
HTH