In my experience, dandelion doesn't compete. I have little difficulty
digging it up in such a way that it stays dug. But I agree about
thistle (assuming we mean the same one).

Nick Maclaren.

Probably. The tricky bit with horseradish is the depth of the roots - the tap
roots seem to go much deeper than dandelion and thistle. I'd recommend trying the
sauce by the way - It is much better than the shop bought version. As I understand
it manufacturers are required by law to pasteurise the root - which drives off
most of the volatile aromatic compounds that gives the sauce its pungency.

Regards,
Drakanthus.