Depends whether it was petrol or deisel - deisel is a much more serious issue, the bed will be contaminated, and the plants in it. If it was petrol, that tends to just evaporate.

thanks fo r this, really appreciated. I think it was petrol will ask when he comes back, it was pink coloured and smells like petrol, the rhubarb is wilting, have dug it up and hosed all soil off it, wondering if I should put some sand in the soil to soak it up

I got petrol in my eyes and all over my coat once (faulty pipe at the petrol station) and was told by the hospital that it just evaporates - I think that's probably right because my jacket, which was soaked, didn't smell at all a few hours later. It will, though, have probably been enough to kill off some of your plants, and I'm not sure I'd want to eat them.

have decided to bin the affected plants and the rhubarb as I will not really have confidence in cooking it now, it is not worth taking a chance, new meaning to flambe` rhubarb crumble!! just need to fire the tree chopper now for destroying my herb garden! thanks for the advice

He's liable for replacing your plants too...

I'd dig out the soil to a depth of 6 - 12 inches and replace to ensure there is no contamination. Stack the contaminated soil in a corner for a year or two to allow the petrol to dissipate. Advice from Mr MB who used to be with the environment agency.

Ah, good - that's useful to know, for both me and you, Spoiledrhu...

I remember going on an emergency call out with himself on a Sunday. The owners of the property had been away for a couple of weeks visiting family. On their return the discovered that some vandal had drilled a hole in their oil tank. Not only had they lost a huge number of plant but, being on a disability pension, they could not afford to replace the oil tank. If I could have laid hands on the young thugs who had done this I would have wrung their necks. The saddest thing was the auld wifie weeping over a rose given to them as an anniversary gift...

Here in the desert we use commercially available humates and/or composted manures and earthworm castings as a way of accelerating the decay of oils or petrol in the soil. It still takes at least a year or two, and may take even longer in cooler climates like the UK.

Thanks to everyone for all the advice, have found it all very useful. I have dug out the soil to about 6 inches and discarded it to a corner, but will now dig it deeper just in case, have disposed of the rhubarb as well, which is so annoying.

Very annoying send a bill for the cost of new plants.