Snip the plant. It is much easier to grow rosemary from a plant that is already established. Getting rosemary to germinate on its own is not only tough, but the seeds often produce less than impressive results. The first thing you want to do is snip a two inch piece from a new growth on an established plant.
Purchase a rooting hormone. These can be found in any garden store.
Remove the bottom leaves. Do this from the last inch of your piece of rosemary. Then submerge that end in the rooting hormone.
Place rosemary in starting seed mix inside a planting container. Place the end that was dipped in the rooting hormone into the starting seed mix. Make sure it is made of peat moss or something of the like so that it can drain well.
Find a place where your rosemary will receive indirect sunlight. Place the plant there.
Water lightly. Over the next few weeks, water the rosemary sparingly, making sure the soil stays damp.
Gently "tug" your plants. After 2 to 3 weeks test your plant by gently tugging to see if a proper root base has formed. If the plant holds the soil then it is ready to transplant to your garden.
Transplant your rosemary. Dig 2 inch holes in your garden and transplant your rosemary. Soil type is not imperative as rosemary seems to adapt well to different kinds of soil. Just be sure your soil has proper drainage. If you are concerned about drainage, consider adding compost.