Why Is My Rosemary Turning Brown? (Read This First!)

Why is my rosemary turning brown?

This isn’t an uncommon question; the simple answer is, in most cases, rosemary usually turns brown due to root rot or fungal issues. Sometimes though, your rosemary could turn brown because it isn’t getting enough water. The answer isn’t simple; you need to learn how to grow rosemary properly if you want it to thrive.

Find out how to resolve these issues and enjoy healthy, beautiful rosemary. 

Indoor Rosemary Plant Turning Brown

Rosemary is a popular culinary herb native to Mediterranean areas. As such, it prefers dry growing conditions, and this is where some people have problems. Often, people keep their plants in too-damp soil, resulting in an indoor rosemary plant turning brown. 

Damp soil occurs when the soil doesn’t drain well or due to an overzealous watering schedule. You may even have damp soil when the humidity is too high or if there is too much rain and your potted rosemary is outdoors. Because rosemary doesn’t require as much water as most herbs, the roots will start to rot if it receives too much. 

However, don’t make the mistake of underwatering, either. While rosemary likes dry environments, it doesn’t mean you don’t have to water it! Limit watering to once every two weeks or so to prevent the soil from getting too wet. You can easily test the soil before you water it by sticking your finger into the soil. If it feels dry, your rosemary would probably like a drink. If the soil feels moist, you can wait a few more days and check again.

Outdoor Rosemary Turned Brown in the Winter

If your rosemary turned brown in the winter, you could be dealing with one of two problems. Either the melting snow creates too much moisture in the soil, or it’s too cold outside for your rosemary plant. If your rosemary is outdoors, either of these could be possible because, in cold climates, cold, wet soil means root rot for your rosemary. 

Remember, rosemary likes warm, dry conditions. If you want to grow rosemary outdoors, you should be in USDA growing zones 7 through 10. Depending on your microclimate, you might be able to pull off outdoor rosemary in zone 6, but there is no guarantee. 

To improve your chances of success, try a cold hardy version. However, even in this case, if your temperatures get below 30 degrees Fahrenheit, it will be too cold for your rosemary, and it is likely to turn brown and die. The ideal temperature for rosemary is between 55 and 80 degrees.

How to Grow Healthy Rosemary

Rosemary naturally grows wild on rocky or sandy hillsides that drain quickly after rainfall. Its native environment is characterized by dry heat, low humidity, and infrequent rainfall with full sun. You should keep these factors in mind as you grow rosemary at home. While rosemary can adapt to less-than-ideal conditions to an extent, you should keep growing conditions as close to ideal as possible for your plant to thrive and be happy.

The first time I bought a rosemary plant, it was fairly large and shaped to resemble a Christmas tree. I bought it because it was cute, but I hadn’t researched how to grow rosemary, so I left it outside through the cold Wisconsin winter, and it died.

My next attempt went much better. I still grew my rosemary outdoors but brought it inside for the winter. Here is how I was able to grow healthy rosemary successfully.

First, make sure you have the right soil. A blend of potting soil, organic compost, and sand will create a nice growing medium for your plants. Choose a warm, sunny location for your plants that will mimic their native environment as closely as possible. Ensure that your plant is located in a well-ventilated area. A location that doesn’t allow for adequate airflow could cause fungal issues for your plant.

Once you have the right soil and location, you can pot your rosemary plant. Choose a pot that offers drainage, so you don’t have to worry about your rosemary getting “wet feet.” Your pot should be one size bigger than the pot your plant came in to allow for growth without dwarfing your plant.

Put your plant at the same soil level that it was at previously, and tamp the soil down to ensure there are no air pockets around the roots. Now give your plant a good drink to help it get over the shock of transplanting. 

Bringing Rosemary Indoors

I like keeping my rosemary outside during the warm months of the year. But it’s time to bring it inside when the weather gets cooler. Before you do, make sure to follow a few steps.

First, check your plant over. Look for dead branches or areas that just need some trimming. Take care not to prune more than one-third of the plant. Check carefully for white or grey spots on the leaves, which can indicate fungal growth. These areas should be pruned off, followed by spraying your plant with a fungicide to prevent further issues.

You should also check for insects. As the weather cools, insects look for a good place to spend the winter, and that’s usually in your plants. Some of these insects may damage the plant, while others might just decide they want to find a cozy spot in your house or your other plants. Either way, you don’t want them in your house. I like to spray my plants with neem oil before bringing them inside. Neem is a wonderful natural oil that discourages insects and also works as a fungicide. 

Once that is taken care of, I place my rosemary in a bright, warm area of my home. One important thing to remember is if you use a humidifier during the winter months, this is not where you want to put your rosemary. Your other plants may love the added humidity, but rosemary will not.

You won’t need to water your rosemary as often during the winter. Winter is when most plants rest, so they will not grow much during this time. Always use your finger to test the soil before watering.

How to Revive a Rosemary Plant With Brown Leaves

Is your rosemary wilting and turning brown? Too much moisture causing root rot is the likely culprit. To fix the problem, remove the plant from the wet soil and clean off the roots with room-temperature water. Inspect the roots for damage and prune away dead roots and roots with any fungal growth, being careful not to remove more than one-third of the roots.

Replace the old soil with a mix of sand, compost, and potting soil to allow for better drainage. Rosemary needs loose, well-drained soil that doesn’t hold water close to the roots. Once you have this type of soil, you can re-pot your rosemary. Wait about a week before watering, and keep your rosemary plant in an area that doesn’t have direct sun during this time. This will allow your plant to recover with minimal stress.  

FAQs

Can You Use Rosemary After It Turns Brown?

Rosemary isn’t usually good for culinary use after the plant has turned brown, as it will lose its flavor and scent. It won’t hurt you but it won’t help you, either.

Should I Cut Back Brown Rosemary?

Areas of your rosemary that are brown and dry can be safely pruned with no problems. These areas are dead, so they don’t affect the living part of the plant.