What is my greenest choice for a patio or deck material?
I have a small yard in Northern Virginia.
Tricky question as to what is "greenest" -- you can look at this in different ways.
Some would say a wood deck is greener since wood is a renewable resource and something like concrete has a higher embodied energy. With that said, I would go with the product that has the better durability and will require less maintenance.
There are many new interlocking paver options out there -- this will probably cost less than a wood deck and will not require staining and sealing every year. If you are concerned about an impervious area, there are also some pavers that are pervious to allow rainwater to infiltrate into the ground.
For more information:
You should also read Marian Keeler's Ask A Pro Q&A, "What are the best green alternatives to wood for decking?"