explain to me

 … mattock …?

No fighting for land raised lettuce, mature or not (6) 

No, there isn’t so much as a sprig of endive.

No fighting for land raised lettuce, mature or not (6) 

There’s a charade, reversal indicator, another charade.

_ o _ _ _ _

Yes. You have pinned it down.

No fighting for land raised lettuce, mature or not (6) 

WORDPLAY

raised [reversal indicator]
   lettuce [charade: cos]
   -> soc

mature or not [charade: age]
soc+age

WHOLE DEFINITION

no fighting for land = socage

Over to you, nfs.