I have an acre of lawn. It has been getting harder to cut it, each year I have to raise the mower as it is getting so thick and stalky. When I separate the grass to look at the stems, the bottom half of the grass is all yellow. There is quite alot of moss aswell. I plan on using sulphate of iron this year, would scarifying and then fertilizing help? I also use weedkiller on it every year for clover and daisys etc. It looks more like a field than a lawn at the moment. What would you advise to help get it nice looking again.
You should cut it down hard, perhaps in two mowings, or using a more powerful mower, and do not allow it to build up again and mow more regularly.
Scarifying would help but it is a lot of work on an acre and harder mowing with give a smiliar result. Feed enough to keep it growing but not too much if it is growing well. Use sulphate of iron for moss.