Technically speaking, yes, a boxspring will work under an Avocado Green Mattress.
However, the Avocado Green Mattress is best suited for firmer, non-yielding surfaces, to include platform beds, mattress foundations or bed slats within a bed frame placed approximately 5" apart or less. In short, anything that does not contain springs.
Why? Because a boxspring, like the name suggests, actually contains innersprings. Using a boxspring with an Avocado Green Mattress tends to make the sleeping experience too "springy" for most customer preferences.
If you are not sure, try adding a bunkie board (shown below, from Crate & Barrel®) or piece of plywood between the boxspring and the mattress. The flat surface will offer firm, non-yielding surface that is ideal.
(Note: Foundations do not contain innersprings and provide a rigid support surface.)