Green Manures - friend or foe?

Hi there,
I have recently acquired a new allotment space and I'm ready to embrace the journey,

First of all I've been looking into improving the soil in preparation for a productive next season. I've been looking at Green Manure plants. They seem like very exciting options - only, I have a question which I can't seem to find an answer for -
Whats to stop a green manure plant such as alfalfa, a clover or mustard, becoming a weed? For example, if they are a perennial plant as some are - can they be 'weeded out' when they are no longer wanted? What if they are self-seeding - couldn't they end up being an unwanted weed at some point in a rotation because the seeds are all over the place? Please share any thoughts....


T


- I should add, I'm looking to use in as much as is possible a no dig system - so annual green manures would be perfect as they'd die off in the winter - but then the seeding question comes into play - and as for other perennials, would they persist if they are mowed / cut at the base, or would the plants die and roots decay as would be desired? Again, any shedding of light in my inexperienced mind would be much appreciated..

T

Phacelia is the best, it is a go anywhere green manure others are legumes, etc!

I have used it quite often, provided you cut it down the day before you dig it in

My OH said that if I ever use green manure again I can dig it in myself!

It was rather painful to get rid of I must admit!

You could try lots over wintering broad beans Aquadule Claudia would be the one .

As I understand it you have to dig the green manures in as seedlings before they get big enought o seed so there's your "no dig" out of the window - unless I'm mixed up here?

Clovers fix notrogrn in the same way as legumes though don't they so even if you're harvesting the tops you would still need to dig the roots in?

Yes the roots are already in  but they're relatively close to the surface aren't they?  Do they need to be dug in prior to planting anything else or will they just decompose over time?  The point is the OP was saying s/he wanted to use green manures on a no dig system without the green manure taking over the plot like a weed but I don't see how you can have both really.   I thought the whole point of green manures was that you dug them in before they had a chance to become huge & a hence a massive chore.