The answer to 'why is my landscape lighting brown patches' is that the brown patches are likely caused by a problem with the lighting system or the surrounding landscape. Common causes include improper installation, electrical issues, or damage to the lights or wiring.
Some symptoms to look for include dimming or flickering lights, lights that won't turn on, or areas of the landscape that are not evenly lit. Solutions may involve adjusting the lights, replacing damaged components, or addressing any electrical problems. If the issues persist or you're unsure of the cause, it's best to call a professional landscaping technician to diagnose and fix the problem.