Rosemary benefits from being placed outdoors during the growing season. Move it outside in the spring after the threat of frost has passed and temperatures range between 40° and 50°F at night and below 60°F in the day, place it in light shade where it is protected from the wind, and return it indoors before the first hard frost in the fall. It can usually tolerate high temperatures but will not tolerate freezing temperatures.
Water thoroughly, but make sure to allow the excess water to drain so the roots and bottom of the soil are not soggy. Overwatering can cause root rot. Allow the top 2 inches of soil (approximately) to dry before watering again.
Apply a complete liquid fertilizer every 4 weeks at 1/2 strength throughout the growing period, typically from spring to midsummer.
Jackson & Perkins offers a selection of fertilizer & plant care products. We suggest using AlgoPlus fertilizer for the general health and maintenance of your plant.
When your plant has outgrown its current pot, transplant in early spring, if possible. With each repotting, increase the pot diameter 1 to 2 inches in size and use fresh, high-quality potting soil.