Interested to read your article in the Daily B. Made me smile as this has happened to me some years ago, how industrious ants are!
I remember seeing a solution (though different climate, on Monty Don programme) that having scattered the seeds on prepared ground and preferably a bit sandy, you should then lightly cover them with a coating of fine earth then press down and water well.We have “a lawn” under the fruit trees in our orchard (s/e Majorca) and it's quite a mixture of grasses and weeds!
The “Rustic”/Gram” grass seems best to withstand the summer heat and spreads on its own.I do actually mow it weeds and an all, and it´s about the best we can manage in this climate, under trees the lawn is better.
When I planted the orchard and started on the gardens some 25 years ago, I remember that I saw the plants that seemed to do well in the other fincas in the area, and planted them.
I had tried to grow bananas/rhubarb in another finca in another area of the island with no luck at all. So checking out the my neighbours fincas have been lucky with most plantings. Good luck with the lawn.