Great question! And one that is built into the scenario of a single location business expanding to new locations.
There are typically 2 routes local multi-location businesses can take.
-
Build a single set of service description pages + a unique page for each location.
-
Build pages for every possible keyword/city combo + a unique page for each location.
Benefits of route one: by focusing your resources on this more limited set of pages, you may find you've got what it takes to build the BEST page on, for example, native plant landscaping in the industry and the BEST page about your location in San Francisco.
Drawbacks tend to relate to how to optimize major pages of the website (homepage, about). With just 2 locations, you can likely include some optimization for both cities on these pages, but if you start opening numerous locations, this can become untenable. After all, Whole Foods does not list hundreds of cities on its homepage ;). And, once you've got these two sets of pages built, you can turn focus in all kinds of exciting directions, creating all kinds of new content that continues to build your brand and increase conversions.
Benefits of route two: If you have the resources to do this well, you can end up with some very thorough keyword coverage. However, it may or may not be great for human users. Will users genuinely be helped in some unique way by the presence of your page on 'native landcaping san franciso' and your page on 'native landscaping oakland', describing the exact same service twice? In some cases, yes, but in others, no. So, make a wise choice here. Does a set of pages covering every possible service/city combo exist for users, or because you're crossing your fingers search engines will take note?
Drawbacks become quickly apparent where resources are lacking. Thin, duplicate content can easily result from this route, weakening your website instead of strengthening it. With proper resources, this doesn't have to be the case, but if you suspect it might be tough to pull off dozens of truly top quality pages with the route 2 approach, I'd advise sticking with route one.
Hope this helps, and Rand's most recent Whiteboard Friday might help with organization of the work ahead of you: https://moz.com/blog/build-content-keyword-map-for-seo-whiteboard-friday