My lawn has been turning yellow over the past few weeks, even though I water it every night. I've already tried adding NPK fertilizer but it didn't help. Could it be a nutrient deficiency or some kind of disease? I live in São Paulo and the heat has been absolutely crazy.
When I'm on the road far from home, I see a lot of this in the lawns at gas stations and rest areas, especially with that São Paulo heat. The problem could be a combination of extreme heat with nighttime watering - the grass is suffering thermal stress and watering at night leaves the lawn humid during the hottest hours of the day, which promotes fungi and even salt burn from salt concentration. Try watering early in the morning, really deep but less often per week (like 2-3 times), and check if there's no white fungus or dark spots - if there is, you might need a specific fungicide before adding more nutrients. NPK will only help if the soil has aerated space, so if the soil is compacted from use, aerating the lawn makes a difference.
Log into answer.
