Looking for some feedback.  I have a sunny location at the corner of a parking lot where I am thinking of planting a fig tree.   The problem is, many years ago some asphalt roadway, or paving, was scraped up and pushed to the perimeter of the lot to enlarge it along a gully.  Drainage would be good, but my concern is planting a fruit tree in dirt and gravel with large chunks of asphalt burried underneath. It is mostly dirt and gravel, which is just fine, but  the asphalt chunks I am wondering about. 

Would the oil in the asphalt injur or stunt the tree or contaminate the fruit?  Any thoughts?

if there truely is asphalt mixed in or near the grow zone,  I would be hesitant,,, no science here, just gut.

I have seen one tree that was surrounded by asphalt and was old enough that it would have been there for a few oilings. So I don't think it will hurt the tree, especially if the asphalt is old and has been mixed with soil.

I only did a little research to find out the dangers of asphalt in soil but it seems that what is troubling are polycyclic aromatic hydrocarbons. From what I gather they are persistent in soil but also not readily taken up by plants. Suggestions for their cleanup include things like adding organic materials and NPK to the soil to boost microorganism activity. It is also important to note that the plant part that would be highest in any toxins is the root system which is in direct contact for the soil. here is the paper I browsed through

However, I'd be hesitant to eat any fig that grows in such a spot.  Like Greg from Arkansas, I'm not saying that scientifically, just gut.  I doubt that it's been studied well enough to answer enough questions about what compounds are taken up by the tree and end up in the fruit (or in this case, in the flower).  Brent - glad you actually looked for studies, but what about the compounds they didn't look for?  (How's the Bromberg song go?  "Just because you didn't answer, doesn't mean I didn't call".  In other words:  Just because they didn't look for it, doesn't mean it isn't there).

Mike

Go for it!!!!!

I say plant it!  Figs are like weeds, might end up being the best location for it!

Put it there is an oversized pot. Now you have the best of both worlds.

Some of my best fig trees  grow in a mix of dirt (who knows from where) limestone gravel, asphalt and coal chunks, gypsum wallboard and cement  chunks.  I did not chose that amalgam, it was the only available soil behind our store.  It is basically an alleyway and past catchall for whatever.. I say just do it.

Well Pete, I wish I never looked so hard into this. Turns out asphalt is used to line many public water system pipes and it is impossible to know what exactly is in it because the contents vary by region and recipe.

Some PAHs are readily degraded in soil with high microorganism activity, and some are not. From what I can gather, for the most part they are not taken up through the soil as much as through leaf pores from the atmosphere and dust, which is where most of our exposure to these comes from already. I am not a scientist and parts of the papers I am looking at are certainly over my head. I do remember Bio 10whatever though and correct me if I am wrong but plants do not use carbon from organic materials in the soil right?

Great discussion and comments guys.   We planted it in another location, partly based on gut feeling, and partly because I don't know what else may buried there.   It may be a future site, but we'll want to do a bigger excavation than I can do with just a pick and a shovel in an hour or two.

Thanks to all of you.