Q.Brown patches of Grass
We moved into the house in March…. the grass looked good… now there are a bunch of brown patches. We used a mower with sharp blades after the 3rd mowing… Please help with the brown patches. We live in New England.

There are a number of reasons that could be attributed to the patches of die-back you show in the photo. Insect pests, fungal disease, soil borne nematodes, watering irregularities and soil nutrient deficiencies are included. You may need an on site professional assessment to get to the bottom of it. There may not be a magic fix, but instead you may need to approach the soil and water management in a comprehensive way.
You are fortunate to have in New England an active community of Organic Land Care and Organic Lawn Care professionals and lots of information on how to do it yourself. Search this term - "organic lawn care connecticut" and you will see several resources.