We had some turf laid in the garden of our new build about 6 months ago.
Most of it has taken well. However, for about a 3 feet in width along
the length of a north facing wall that we border, the grass is very
thin. When its cut, there is quite a bit of mud, and the grass that is
there is patchy. I would like to sow some additional seed to try and
bolset the turf. What type of grass seed should I go for, and any tips
on sowing ?? (when to do it, quantities, watering etc etc)