We can't see enough detail in the photos to determine the cause of the browning, but there are several possibilities. Soil moisture level can definitely contribute to browning if the grass gets too dry, but the only way to judge if watering is needed is to check the soil moisture about four inches or so below the surface. (If somewhat dry to the touch at that depth, watering may be needed. If damp, watering should not be needed.) Prolonged grass blade wetness, such as from a rainy stretch of weather, very high humidity and/or dew, or irrigation late in the day can all create conditions where fungal spore infections are more likely, since the pathogens can more easily infect leaf surfaces when they are wet for long periods.

Several fungal diseases can cause browning in turf, and unfortunately their symptoms can overlap greatly. If mycelium (the actual fungal "body") becomes visible on a dewy morning or after a night of rain, its color can point to one pathogen over another, but if not visible, it can be harder to diagnose. Brown patch, pink patch, red thread, and gray leaf spot are all fairly common turf diseases, with the first three already being prevalent so far this growing season. Fungicides are not recommended for those infections because they will not cure existing disease and because the grass usually recovers on its own as the weather changes.

We are not familiar with the fertilizer product you mention (FloraNova Grow), though the manufacturer's website implies it's intended mainly for hydroponically-grown plants, not lawns. In either case, fertilizer of any type is not recommended for plants struggling with disease or decline because it won't resolve the issue and could worsen symptoms. It's always good practice to perform a laboratory soil test on the lawn (every 3 years or so, at least) before applying fertilizer. That way, you know what nutrients might actually be needed, and if the soil acidity (pH) is in the right range for those nutrients to be available to the turf. Maryland has a lawn fertilizer law that prohibits applying phosphorus to lawns where the soil has not tested as deficient. Any nitrogen applications also need to be accounted for as part of the total nitrogen dosage for the year to avoid exceeding those limits as well. For some turf infections, applying a light dose of nitrogen can improve recovery, but for others, fertilizing can worsen the disease.

We suggest you continue to mow high (the highest mower setting, which usually means at cutting height of about 4 inches). This will minimize mowing stress on the turf and reduce weed competition since the grass can shade-out more weed seeds at that height. Low-mown turf is also more vulnerable to drought stress since the soil surface is less shaded and can heat-up and evaporate moisture more readily on sunny summer days.

We also suggest that the lawn be overseeded with any of the recommended turf cultivars (even if you can only find a seed blend using one of them) later this season (around September, the ideal time for seeding tall fescue). If the soil is compacted or hard to re-wet once dry, core-aerate the lawn before seeding. If you use a mulching mower (one that chops-up the cut grass blades and returns them to the soil instead of bagging them), that will help gradually build-up organic matter in the soil, to the benefit of turf roots and the soil's moisture- and nutrient-holding capacity. The lawn pictured looks not very dense, though we can't tell whether that's from some leaf blade die-off or just poor soil conditions.

If you would like to send additional close-up photos of any lesions on the grass blades, suspected mycelium, or the pattern of browning, feel free to do so, though it can be difficult for us to narrow-down a diagnosis to just one ailment from photos. If fungicide use were warranted, often it's best applied by an experienced lawn care company (plus, some chemicals might require a certified pesticide applicator if they happen to be restricted-use).

Miri