We added an additional above ground bed today.
These modular kits were purchased at Home Depot. They are economical and readily available, but the best part is that as your gardening efforts expand your gardening can easily expand also.
We also prepared our Earthbox gardening area with some additional leveling pedestals. These were actually recycled from our backyard. The previous owners used the pavers in the backyard, so re-purposing them was pretty easy.
In the next couple of weeks we will finish leveling the pavers and prepare our Earthboxes. The backyard deck works well because our vegetables have a practical place to "climb".