Rhubarb & Green manure

This may be a daft question for which my apologies:
I've got a rhubarb plant which I was planning to divide and move this winter. It's in desperate need as it has about 5 heads all clumped together so really needs splitting (previous owners seemed to have abandoned it, however I didn't want to move it the first year we had the garden). It's just started to die back so I'm plotting to move its plot soon.
I have a new plot for it all ready, lots of good compost for it, however the green manure of forage rye that I put in has hardly got going. Now I know that forage rye puts down a chemical that stops seeds from germinating but isn't supposed to be too harmful to established plants.
So basically i was wondering what people's thoughts were on a green manure such as forage rye on the rhubarb plot as a weed suppressant during the winter period. It's not something I've seen mentioned before in guides and I don't know if it's not done because there is no point, or if it's not done because it is harmful. This is particularly of concern to me now if I am moving the rhubarb to a plot where the rye is established (Ready to be cut back in late winter/spring when the rhubarb starts to grow again).
I may just play it safe, but where's the fun in that 

Thanks, it was kind of what I was thinking but I think I needed a second voice.

One of the reasons i stuck in the rye was that that plot is pretty much entirely compost, manure and council soil improver, i was a little concerned I had overdone it with the "good stuff" you're supposed to add to the soil before moving rhubarb. I guess the thought was that a good rooting plant would healp encourage worms and discourage and weed seeds that might be left in the compost & manure...
Thanks again.

If you plant rye you may find that it is difficult to control.

The correct thing to do with rhubarb is to lift it after all the leaves have died down, split it into pieces with several buds on it, and then leave it exposed to the weather until after Christmas before planting.

Your prepared bed seems ideal. You could cover it with a sheet to surpress weeds until you want to plant the rhubarb.

You may be able to split suitable pieces off the old plant without lifting the whole plant. You can then leave the old plant to crop this Summer while the new plant is getting established. You should not crop the new plant in the first year.