If your lawn is developing irregular brown or yellowish patches and eventually dies, it might well be infected with Anthracnose.
This fungal disease can occur in two forms, Basal rot, occurring during the cooler, wetter months of late Autumn / Winter, and Foliar blight, occurring during the warmer months of Summer when the warm weather is mixed with periods of intermittent rain. It can be particularly serious on annual meadow grass (Poa annua) but can also occur on both bents and fescues.
The fungus (Colletotrichum cereale) normally occurs when the grass is under stress, possibly as a result of low Nitrogen availability, high levels of compaction or very close mowing, and climatic conditions are suitable.
If you suspect that your lawn is infected with Anthracnose fungus why not take advantage of the Lawnscience lawn review service. One of our fully trained, professional lawn professionals will be happy to arrange a free lawn review with you, during which they will identify the issue(s) and provide you with a fully costed solution for you to consider. To take advantage of this opportunity just contact us.