Right, forgot to mention the suggestions included in the report

For low concentrations:

Locate gardens away from old painted structures and heavily traveled roads.
Give planting preference to fruiting crops.
Incorporate organic materials such as high quality compost, humus, and peat moss.
Lime soil as recommended by soil test (a soil pH of 6.5 to 7 will minimize lead availability).
Wash hands immediately after gardening and prior to eating.
Discard outer leaves before eating leafy vegetables. Peal root crops. Wash all produce thoroughly.
Protect garden from airborne particulates using a fence or a hedge (fine dust has the largest lead concentration).
Keep dust in the garden to a minimum by maintaining a well-mulched, vegetated, and/or moist soil surface.

For medium concentrations, the above, plus:

Restrict access of children to these soils by maintaining dense cover.
Do not grow leafy green vegetables or root crops in this soil. Instead, grow them in raised beds built with non-contaminated soil and organic amendments.

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http://www.grayenvironmental.com/lead_in_garden_soil.htm - suggests that if there are not children playing in the yard, plants can be safely eaten from soils with soil lead levels up to 300 ppm for leafy and root type vegetables, and 500 ppm for fruits and vegetables where the fruiting parts are eaten. So some of our yard could support fruiting foods in addition to the low concentration area where leafy greens and root crops are ok. Mostly, washing things will be important.

Continued reading on phytoremediation suggests that attempting it without the chelating agents may be entirely useless. Still, worth a shot, I think.