Help with new build garden please :-)

Thanks all for your input. My main concern is why am I getting these yellow patched appearing? Am I cutting too much? Taking too much off? Watering too much or not enough?

See picture seems to be lots of yellow.

 

@Infallible - The lawn has come a long way and is looking quite decent.

Agreed with @shiney. Cutting too low can create yellow patches, especially if the ground isn't flat. Even tiny bumps that are unnoticeable by the eye can create brown patches. Also, pulling some some mowers backwards can create swirl marks.

New grass grows at a tremendous pace so mowing at least a couple of times a week is necessary. Although it's impractical in most situations, it's ideal that not more than a third of the grass length is cut off during each mow. If it grows a few inches a week and is cut only once a week, it will cause yellowing.

There has been so little rain recently (at least in the East of England) that grass is seriously suffering in many gardens and so a soaking in the evening every few days will help a lot too.