Why did my rosemary turn brown in winter?

Rosemary plants can turn brown in winter due to a few reasons, such as cold temperatures, lack of sunlight, or overwatering. Cold temperatures can stress the plant, causing it to turn brown. Additionally, reduced sunlight in the winter months can also affect the plant's health. Overwatering can lead to root rot, which can cause the plant to turn brown. It's important to ensure that your rosemary plant is in well-draining soil and receives adequate sunlight during the winter months to prevent browning.