Anyone who has an idea why the grass in my garden is looking as though it's dying? It's getting good showers of rain every day or two.

Need more information on growing conditions.  It could be root rot, due to underlying soil quality, poor drainage. Soil preparation is everything, in creating good growing conditions. 

The opposite could also be a factor, if the grass in on a sandy soil base that has not been prepared and buffered with moisture holding amendments. Heavy rains or irrigation can leach important plant nutrients and create deficiencies which will show up as chlorosis (yellowing), other discoloration or stunted growth.

13 hours ago, drtreelove said:

The opposite could also be a factor, if the grass in on a sandy soil base that has not been prepared and buffered with moisture holding amendments. Heavy rains or irrigation can leach important plant nutrients and create deficiencies which will show up as chlorosis (yellowing), other discoloration or stunted growth.

The grass has been good for about 4 or 5 years and the base was well prepared and laid. It is the first time it has looked not very good.

Only other thing I've noticed is quite a few small white mushrooms are starting to appear.

This is the before. I'll get a photo of now later on today.

On 6/29/2019 at 8:05 AM, overherebc said:

The grass has been good for about 4 or 5 years and the base was well prepared and laid. It is the first time it has looked not very good.

Only other thing I've noticed is quite a few small white mushrooms are starting to appear.

This is the before. I'll get a photo of now later on today.

Here is the now.

Local 'lawn man' reckons it's probably been too much fertilizer and it will come back in a week or two. Some parts seem to be recovering. ????

Quite possible, fertilizer burn is common, especially with use of high rates of high nitrogen, high salt-index chemical fertilizer. High salts desiccates the roots, preventing uptake of water and nutrients, no matter how abundant. It recovers only when the salts have been diluted and leached and new roots have generated.  High NPK chemical fertilizers also negatively affect the beneficial soil biology which is all-important in long term soil and plant health.  Chemical dependency is the opposite of organic lawn care that builds on healthy natural processes. 

If this oawn was back home, if I could exclude fertiliser as a cause, I would definitely go for a fungal infection. Do you know what fertiliser was used, and dosage?

If it is a fungus, spraying with some kind of copper solution should help, ask a rice farmer!

On 6/28/2019 at 6:51 PM, drtreelove said:

The opposite could also be a factor, if the grass in on a sandy soil base that has not been prepared and buffered with moisture holding amendments. Heavy rains or irrigation can leach important plant nutrients and create deficiencies which will show up as chlorosis (yellowing), other discoloration or stunted growth.

yep, i agree--though lately here in Hang Dong--not much rain to speak of lately--news says Thailand headed into serious drought.

Could be Army Worm ?