Planting containers, gravel, soil and plastic film are needed to grow rosemary from seeds. This way of growing rosemary is often not preferred due to the time-consuming germination process, but the gardener is rewarded with the easy maintenance, fragrant scent and large size of a mature rosemary plant upon success.
Fill the bottom half-inch of four 3-inch tall pots with gravel for drainage purposes. Fill the rest of the pot with a planting medium composed of 20 percent sand and 80 percent of a fast-draining organic potting soil that contains enough fertilizer to feed the rosemary plant for at least three months. Four or five rosemary seeds should next be placed in each pot and then placed in an area that is exposed only to partial sun at most. The soil should remain moist from the time of planting, and the topsoil should be misted every three or four days if needed. Plastic film can also be used to maintain a humid climate for the rosemary seeds. These seeds need a large amount of heat to germinate. Once sprouts appear, the fastest growing and healthiest sprout should remain, and the other seedlings should be removed from the pot. The remaining sprout should stay in its initial container for six months before being transferred to outside soil.