This is news to me!

1. The Secret Ingredient: Epsom Salt
Nana's secret to a thriving rosemary plant is the use of Epsom salt. Epsom salt, or magnesium sulfate, is a natural mineral compound that can work wonders for rosemary. Magnesium is essential for photosynthesis, and adding Epsom salt to the soil can help improve the plant's nutrient uptake.
To use Epsom salt, simply dissolve one tablespoon in a gallon of water and use this solution to water your rosemary plant once a month. This will provide the plant with the necessary nutrients to promote lush growth and vibrant foliage.
Rosemary prefers slightly acidic to neutral soil with a pH of 6.0 to 7.0. It is also drought-tolerant, meaning it doesn't require frequent watering. However, it is important to ensure that the plant receives enough water during its initial growth phase.
3. Choosing the Right Pot
Selecting the right pot is essential for growing rosemary. The pot should be at least 12 inches in diameter to allow the roots to spread comfortably. A larger pot will also help prevent the plant from becoming root-bound, which can stunt its growth.
Ensure the pot has drainage holes at the bottom to prevent waterlogging, as rosemary does not tolerate soggy soil. A terracotta pot is a good choice as it allows for better air circulation and moisture evaporation.