Posted: 05/07/2014 at 16:15
Hmm, not brilliant I agree - but the poor things have had some competition haven't they?
I'd give the bed a thorough weeding and feed them with some Fish, Blood & Bone and just let them grow for the rest of the summer without pulling any stems. I never take any rhubarb after the end of June, to let the crowns build up. Don't let the ground dry out totally.
Then in the autumn when the leaves have died down remove the rotting leaves and mulch the crowns with well-rotted farmyard manure - don't cover them. In Feb a good feed with more Fish, Blood & Bone and they should be cropping well for you next spring.
The following year you could try putting a forcing pot (or upturned bucket or old chimney) over one of the crowns in early January to encourage some early stems. This isn't 'real forcing', rather more 'encouraging' the crown to produce an early crop.
Stop pulling from the 'encouraged' crown at the end of May. As you have more than one crown you can alternate the 'encouraging' each year.
I never pull more than one third of the stems at any one time.
Hope that helps