You may be able to cut additional turves from a nearby field.
In 1377 he complained of trespassers digging turves at Deepdale, near Scarborough.
Start laying the turves, preferably along a straight edge, butting closely end to end.
Although the time to sow a new lawn has long passed you can still use turves.
The wall, as opposed to the stone structure of Hadrian's, was a rampart made from stacked turves.