Using Vetiver and green mulches in the vegetable garden

I've been experimenting with Vetiver in partnership with vegetable growing.
Rather than create a Vetiver hedge around the bed, I'm growing Vetiver among the vegetables and experimenting with green mulches like the Australian native, Commelina cyanea (aka: Scurvy Weed).
[I'm also exploring Coastal Jack Bean (Canavalia rosea) as a green mulch option in my location.]
I have planted a Vetiver slip every 1.5 metres -- based on my experience of clay pot irrigation (in my sandy soil).These distances have been confirmed by research into clay pot watering.
The Scurvy Weed may be extensive but it is easily managed by pulling and dropping to create a layer of tangled drying stems and leaves. The Scurvy weed is supplying mulch until the Vetiver can be cut back for straw to cover the beds.
I find that one year or so of growing each Vetiver in situ is long enough before lifting and division -- just so long as you leave the bulk of the root mass in the soil. That way, and with a few haircuts per year, the Vetiver won't dominate the bed and the microbiology is undisturbed.