On 30 Jan, 14:33, "Farm1" please@askifyouwannaknow wrote:
Potatoes can be grown very successfully on a lawn provided they are
well covered with hay and that has fertiliser added and the hay is
kept well watered and the hay level is kept topped up as the pototoes
emerge and as the hay collapses back on itself.
We now always grow our spuds this way as I always have spoiled hay
around. It's a good and very easy way of ending up with an enriched
bed for another crop in the next year's rotation.

The OP's mother would require 15 cubic feet (10cm) of manure to
successfully grow its spuds in the no dig method - plus the continuous
add ons of mulch, and more importantly the thousands of little workers
which is required and which we call worms. Without these there's no
chance of a successful crop. The only chance there is is if the lawn
has been previously cultivated and put to lawn recently and more to
the point entirely organic which promote a healthy worm population.
The potatoes will not be able to penetrate a thick layer of lawn roots
and weeds.