Dying Rosemary Causes and Cures

Rosemary is now considered part of the Salvia genus and is native to southern Europe. The plant is used in cooking and aromatherapy due to its savory flavor and aroma. Dying Rosemary can occur when the plant’s primary care needs are not being met. If your Rosemary is showing signs of stress, it is likely caused by one or more of these common mistakes. 

Overwatered Rosemary

Rosemary has low water needs, requiring just enough to keep the plant hydrated for photosynthesis and growth. Overwatered Rosemary first shows signs of stress with brown tips on its leaves. The browning is caused by the plant’s roots failing to absorb any more water or nutrients because the entire root system is already oversaturated. The result is a plant that begins to die from starvation. 

Proper watering of your Rosemary plant requires you to allow the soil to almost completely dry out between waterings. When grown in the garden, water only when the soil is dry and rainfall has been low. A deep watering once per week is often enough. When grown in pots, the soil is easily tested for moisture before watering. Insert either a finger or a wooden skewer into the plant’s soil. The top two to three inches of soil should be dry before you water the plant. 

In addition to negatively affecting the health of your Rosemary, overwatered Rosemary also suffers in flavor and aroma. When Rosemary is allowed to struggle a little, through short bouts of drought between waterings, the plant naturally creates more of its essential oil. It’s this oil that gives this herb the flavor it’s prized for and the distinct aroma that makes it popular in aromatherapy.  

Underwatered Rosemary

Insufficient water will also cause Rosemary to suffer. The plant will begin to turn brown, along with becoming dry and brittle. Correct this issue by giving the plant a deep watering in either the early morning or evening when temperatures are naturally lower. Allow the top two to three inches of soil to dry out again, then water once again. Along with these waterings, feed your Rosemary plant once with a seaweed-based plant fertilizer to help the plant recover. 

Rosemary Plant Dying: Poor Pot Choices

Rosemary adapts and grows well in containers either inside or outdoors. To help keep your plant’s roots remain as healthy as possible, the pot you grow the plant in makes a difference. Choose an unglazed terra cotta or clay pot which will wick up excess moisture in the soil to help avoid saturated roots.  Drainage holes are a must have in your Rosemary’s pot as they allow excess water to drain out after waterings. 

If your Rosemary is already growing in a pot without drainage holes, and you don’t want to repot the plant into a pot with holes, create your own drainage by drilling holes in the bottom of your current pot. 

Dying Rosemary: Incorrect Soil 

The type of soil you grow your Rosemary in also impacts your plant’s overall health. If the Rosemary is planted in a garden bed, ensure the soil is not a heavy, clay based soil. These heavy soils do not promote proper drainage and your plant will suffer with root issues. Amend heavy soils by laying a 2-inch layer of sand or peat moss on the soil’s surface and using a garden fork to work it into the soil. If you live in an area with exclusively clay soil, and amending the soil isn’t feasible, consider removing your Rosemary and planting it in a raised garden bed or container

For Rosemary in containers or raised beds, average potting soil is adequate. Rosemary does not require a nutrient-rich soil and, in fact, will produce more of their essential oils if the soil’s condition is somewhat poor. 

Rosemary Plant Turning Yellow and Dying

A common issue gardeners encounter when growing their Rosemary plants in the garden is incorrect pH levels in the soil. Rosemary prefers a soil pH level of between 6.0 and 7.0. If the pH of the soil is acidic, below 6.0, the ability of the plant’s roots to absorb nutrients is affected. The plant will begin to turn yellow and, eventually, you’ll have dying Rosemary if the issue is not corrected. 

Perform a soil test to determine the exact pH level of your soil. If the soil’s pH is below 6.0 and the plant’s health is suffering, raise the alkalinity in the soil. Add limestone to your soil at a rate of between two and three and a half pounds per 100 square feet, depending on your soil type. Another method is to mix a tablespoon of baking soda to a gallon of water and water your Rosemary plant with the mixture. 

Sunlight for Dying Rosemary

Rosemary prefers full sun for optimal growth. Yellowing leaves is one sign that your plant is sitting in shade for too much of the day. If your Rosemary is not receiving between six and eight hours of direct sunlight per day it is recommended to move the plant to an area that does. 

Temperature and Humidity for Healthy Rosemary

Rosemary is native to the Mediterranean and thrives in warm, dry climates. Cool and damp conditions promote soggy soil, and will often cause fungal issues. Maintain temperatures between 55 F and 80 F (12 C to 26 C) and humidity between 45 and 55 percent. If temperature and humidity is an issue, try growing your Rosemary in a container that sits on a porch, deck, or concrete surface where temperatures are naturally higher and humidity lower. 

Dying Rosemary From Root Rot

When overwatering has been an issue for a while, without being corrected in time, root rot will often set in. When rot attacks the plant’s roots, the health of the plant is dramatically affected and your Rosemary will eventually die off. 

The primary solution for root rot is to decrease watering to only when the soil has dried out, as recommended previously. Next, remove the plant from its container or garden spot and inspect the roots. Prune away any dark and mushy roots and treat the remaining roots with a fungicide to prevent recurrence or spread. Lastly, if your Rosemary plant is grown in a container, repot the Rosemary in fresh soil. 

Rosemary is a hardy herb that is very rewarding to grow and enjoy. Moisture issues are the biggest enemy of this plant, with sun and temperature rounding out the top three factors to good health. When Rosemary is dying, ensuring these three elements are correct will often fix most of the health problems that arise with this popular culinary favorite. 

Dying Rosemary FAQ