Rosemary is a drought resistant herb that should only be watered when the soil has dried out around the roots. Water rosemary with a generous soak so that excess water trickles out the base of the pot, then wait for the soil to dry again before watering.
Rosemary is well suited to container cultivation. When grown outdoors in pots or containers, use an organic 20-20-20 non-acidic liquid fertilizer, applied every other week, while daytime temperatures remain above 50 degrees Fahrenheit.
Rosemary is easily grown in a garden with full sunlight (six to eight hours a day) and good drainage; these are the essential requirements. Well-rotted manure added to the garden soil will encourage new growth, but it's not usually necessary.
Temperature: While rosemary survives below 30 degrees outside, inside keep the temperature in the 55 to 80 degree range. About 60 to 65 degrees is best. Air circulation: While not something usually mentioned, air circulation is important.
Rosemary is described as a woody, perennial herb that can become a bushy shrub. The leaves are evergreen and needlelike in shape, and they produce the essential oil that gives rosemary its characteristic scent. They are dark green on the upper side, and the underside has a dense covering of short, white, woolly hairs.