[Eblana]

The plots behind mine and my two neighbours (four plots in total) have been vacant for the past three years because they are problem plots with Marestails (which are thankfully at the far end of the plots).  They don't drain well where they meet our plots.  We have had a lot of problems with weed invasion from them, one of my neighbours asked permission to plant a row of comfrey at the end of the plot behind him which the site owner was happy for him to do, he said at the time if we wanted to extend it right along the four plots we could.  We only did one to see how it went.  It has been brilliant, it is now 5ft high, the drainage on my neighbours plot is great and he has much less weed invasion than us.  It is currently in flower and is covered in bees.  So it is going to be extended!! 

The big question is what to do now with the existing strip.  if it is left as it is will it continue to get taller or will it just collapse down after it is finished flowering.  If it is cut back by a foot or two will it regain its height.  If it is cut to the ground how quickly will it regrow?

[ptarmigan]

I love comfrey - brilliant for the bees.  I cut mine down and it'll come back within a week or two back to almost the same height - really fast.  Dies down completely in winter - but my plot floods and the comfrey comes back every year.   

[GrannieAnnie]

The only thing with my comfrey is that once it rains, it all falls over!  But I can sometimes get 3 flowerings a year from mine!

[yorky]

Yep, as the others have said cut it down. I have got 12 plants of it and I cut 3 of them down each week. At this time of year by the time I have cut the last lot the first ones are ready again. I chop them up and either put them on the compost heap or use them as a mulch around my Dahlias.