Safest/Least Safe Edible Annual Plants for Urban Soil

Hi all,

I'm trying to put together a list of edible annuals which are least likely to take up heavy metals etc from the soil into the edible portion. My suburban yard is not particularly near any busy roads, but you never know, and I can't really afford a thorough soil test at the moment.

So far, I've got this:

Safe (-ish):  beans, pumpkins, tomatoes, chia, amaranth. Things which come from a flower

Risky: Root vegetables, brassicas, lettuce

Any tips would be great

P.S. I took some of the info from this website - https://www.sgaonline.org.au/lead-contamination/

Hi Russell,

Metals are a concern for sure. The website you linked seems to be referencing this study :
http://www.nepc.gov.au/system/files/resources/27b740ab-880f-d7f4-d10e-bab0fa964e48/files/asc-wkshoppaper-10-bio-oliver-uptake-vegies-200301.pdf 

I think the original study is a little less doom and gloom than the website. It gives more details about safe vegetable processing and safe daily intake amounts for heavy metals including how many grams of each vegetable per day would be safe if you soil was contaminated.

A professional test might be expensive, but I know there are home tests available for lead. There might be some for other metals as well. Depending on where you live, you may qualify for a free test from your local government. I assume you are in Australia judging from the links you posted.

Searching around, I could only find information on plants that uptake heavy metals. So if you are worried about your soil being contaminated, you could do a round of bioremediation using so called "heavy metal hyperaccumulators". These plants uptake heavy metals out of the soil and keep them in their tissues. The plants, full of metals, are then removed from the site. There is even research into harvesting the metals from these plant tissues.

A detailed list on wikipedia shows which metals and how much each plant can sequester : https://en.wikipedia.org/wiki/List_of_hyperaccumulators

The only edible plants on the list I noticed were brassicas and sunflowers.