Comfrey

I do dilute the tea, but not in any accurate way - just 'a good glug' per watering can of water. And I do water the leaves (except tomato plants) as well as the roots. I have read somewhere that it's a good foliar feed and I've certainly not had any problems.

But if Monty says...   

I suppose it depends on how concentrated your comfrey tea is?  I know some people on here have their comfrey in an old bit of downpipe, which is fitted up so the 'juice' drips into a container.   So that would be very concentrated.

Did Monty indicate how much comfrey he puts in and how much water?

When I make mine, I jus chuck the comfrey in an old plastic dustbin, fill it up with water and wait.  If I think it looks rather black, then I'll add less of it to the watering can!

As grannie says there are 2 ways of making it - and one of those needs diluting 
http://cultivated-comfrey.co.uk/the-organic-garden/