The answer to 'fence brown patches' is that there are several common causes, including moisture issues, sun damage, and pest infestations. These can lead to discoloration, rotting, or other visible damage to the fence. The best solution depends on the specific cause, but may involve cleaning, treating, or replacing affected areas.
If the brown patches are isolated and not widespread, you may be able to address the issue yourself through DIY maintenance. However, if the problem is more extensive or you're unsure of the cause, it's best to consult a professional landscaper or fencing contractor. They can diagnose the issue and recommend the most effective long-term solution.