I'm curious as to who told you, and why, organic is not a viable option jsut because there is an unknown soil history. That just doesn't make any sense. Were they trying to sell you hydroponics? An organic hydroponics system is problematic and requires tons of attention to maintain (not to mention to set up). I'd say it'd be easier to rip out quetionable soil and replace it than to go to hydropnics. But that brings us back to why is this soil not sutable for growing organicaly.

I've often pondered if one could succeed in flushing hydroponic setups with compost teas and/or other organic fertilizers but really I think that because it is organic material it will bring on unwanted fungi and bacteria. From what I have been taught about hydroponics is that the aim is for a sterile growth environment (hence the lack of soil) to reduce disease, so straight chemical nutrients are flushed through the cycling water. Other than salt buildup, which is washed away this gives the plant what the soil is supposed to (only in excessive amounts and in a form more like a drug rather than a food), as i'm sure everybody here knows. I think the hydroponic system would get plugged up, stinky, and maybe even get anaerobic if organic nutrients were used. Now of course I could be wrong but I've never seen nor heard of any organic hydroponic farm. If anybody knows of any let me know, because i'd love to learn more about it.
-Jen

Thanx for all the great replies, folks!

I guess that seals it - I'm scrapping the hydro idea!

hydroponics = water culture = growing plants in an inert medium (with fertigation as the prime source of nutrient)

yes it is possible to grow organically and hydroponically (organic = carbon); simplest way is to get some coco-coir and use some rubbermaids with holes punched in the bottom as containers, and lids underneath to collect runoff

hydroponics generally precludes the use of ammendments in the medium, so it is a method to feed plants with the fertilizer component contained in the feed water

an addition of 10% earthworm castings to the inert medium provides carbon (humus) and calcium plus beneficial microbes that can help break down nutrients for the plant roots

most garden type plants can be fed with a simple combination of worm box leachate and/or fish hydrosylate and liquid kelp mixed into the water that you will be feeding the plants, which should be pH balanced to around pH 6 in most cases

passive hydroponics is the simplest method, and that is just hand watering the medium as needed (when it gets dry)

you will get the best results growing water loving plants such as tomatoes, peppers, cucumbers, salad greens, etc. which yield well for the space and energy that they require, they are also pricey in the supermarket

with a little research and creativity it is possible to do hydroponics for little cost, for instance clean virgin douglas fir sawdust is a widely used hydroponic medium, and it is free or almost free...leachate from worm bins is a great fertilizer...5 gallon pails for pots...south facing windows = garden

Ah, big problem with that Julie.

You forget that there are places where the land is so damaged and polluted that you really cannot grow an organic garden and it will never pass any of the certification requirements.