I found all sorts of answers, or rather speculations, about this question. The toxins do break down in the soil but I couldn't get a sense of how long that takes. Some say it is OK to plant since only minute amounts would be absorbed by the veggies and of that, how much is passed to the fruit/vegetable; others say build a raised bed and plant away; and others recommend testing the soil for the toxins, oleanderin and neriine. All parts of the plant are toxic and it is so potent that consuming one leaf can be fatal to humans. I can only say what I would do and that is 1. build a raised bed over the area; 2. test before growing in the ground; and 3. not grow edible leaves like lettuces, spinach, chard, etc. I'm sorry I could find a simple yes/no answer.
