The color lasts year round and it thrives in our Middle Tennessee zone 6b-7 area. One one side of the stairs the rosemary's green color contrasts with the light gray-green color of our Russian sage (Perovskia atriplicifolia) and the silvery foliage of a 'Silver Mound' (Artemisia schmidtiana). You can see in the top left picture the edge of the silver mound nudging against the rosemary.
On the right side of the steps the rosemary is backed against a darker shade of green with our asters that should soon be blooming with purple flowers. The rosemary has never complained about not having enough water and in fact seems to thrive in drought-like conditions. If you decide to use it as a landscape planting don't be afraid to use it in your cooking as well, it likes frequent trimmings. The more you clip it the thicker your plant becomes. These rosemary plants are in their second year in the ground and have grown into solid plants that I should be able to use for cooking all winter. If you want a more formal look rosemary can be trained into a topiary or be pruned into various shapes. I prefer the natural look.
You can propagate rosemary cuttings fairly easily since it roots in a cup of water or through layering. Its strong scent can also be a deterrent for deer and rabbits. To date I've never seen a deer on my front steps, but you never know! Rabbits are another matter...