Rosemary is a hardy herb that requires specific watering practices to flourish. Whether you’re growing it indoors, outdoors, in small pots, or large garden beds, knowing how much and how often to water rosemary is essential. This guide will detail the watering needs for different growing conditions and rosemary varieties, and highlight signs of overwatering and underwatering to ensure your rosemary thrives.
General Watering Guidelines for Rosemary
Rosemary prefers well-drained soil and does not tolerate waterlogged conditions. It’s a drought-tolerant herb that needs careful attention to avoid overwatering.
- Ideal Soil Moisture: The soil should be allowed to dry out slightly between waterings. Aim for soil that is dry to the touch on the surface but slightly moist an inch below.
- Watering Frequency: Generally, rosemary needs watering every 1-2 weeks, depending on the environmental conditions and soil type.
Indoor vs. Outdoor Rosemary
- Indoor Rosemary: Indoor rosemary in pots requires less frequent watering than many other herbs. Check the soil moisture weekly and water when the top inch of soil is dry.
- Outdoor Rosemary: Outdoor rosemary benefits from natural rainfall and typically requires less supplemental watering. In dry periods, water every 1-2 weeks, depending on weather conditions and soil drainage.
Pot Size and Drainage
- Small Pots (e.g., Solo Cups): Rosemary in small pots, such as a 16-ounce Solo cup, will need about 2-3 tablespoons of water every 3-5 days. Ensure the pot has good drainage to prevent waterlogging.
- Medium Pots (e.g., 8-10 Inch Pots): For rosemary in medium pots, water with approximately 1 cup of water every 1-2 weeks. Always check the soil moisture before watering.
- Large Pots (e.g., 12-Inch Pots): In large pots, rosemary will need around 2-3 cups of water every 1-2 weeks. Monitor the soil to ensure it is drying out between waterings.
- Ground: Rosemary planted in the ground generally needs less frequent watering once established. Water deeply with about 1-2 inches of water every 2-3 weeks during dry periods. Adjust based on rainfall and soil conditions.
Watering Different Rosemary Varieties
Most rosemary varieties have similar watering needs, with slight variations based on specific types:
- Tuscan Blue Rosemary: This variety is quite drought-tolerant and prefers infrequent watering.
- Arp Rosemary: Known for its cold hardiness, Arp rosemary also requires infrequent watering, similar to Tuscan Blue.
- Creeping Rosemary: This variety, used as ground cover, may need slightly more frequent watering, especially during establishment.
Signs of Overwatering and Underwatering
- Overwatering: Yellowing leaves, a soggy or blackened stem base, and fungal growth indicate overwatering. Reduce watering and improve drainage if these signs appear.
- Underwatering: Wilting, dry and brittle leaves, and stunted growth are signs of underwatering. Increase watering frequency if you notice these symptoms.
Tips for Proper Watering
- Morning Watering: Water rosemary in the morning to allow the leaves to dry out during the day, which helps prevent disease.
- Avoid Watering the Leaves: Focus on watering the soil directly to avoid wetting the leaves, which can lead to fungal diseases.
- Mulching: Apply a layer of mulch around outdoor rosemary plants to help retain soil moisture and reduce the frequency of watering.
By understanding the specific watering needs of your rosemary plants, you can ensure they grow healthy and robust, whether indoors or outdoors. Regularly check soil moisture, adjust watering based on environmental conditions, and be mindful of the pot size and variety of rosemary you are growing.
Need a good moisture meter? This is the one I use.
Sources
- University of Illinois Extension. “Rosemary.” https://extension.illinois.edu/herbs/rosemary.cfm
- Missouri Botanical Garden. “Rosmarinus officinalis.” http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=278040
- North Carolina State Extension. “Growing Rosemary in the Home Garden.” https://content.ces.ncsu.edu/growing-rosemary-in-the-home-garden
- Fine Gardening. “Growing Rosemary.” https://www.finegardening.com/article/growing-rosemary
- Ohio State University Extension. “Herb Gardening.” https://extension.osu.edu/sites/ext/files/imce/Program_Pages/Hort/Herb_Gardening.pdf
