No. I layer some compost and straw on the ground, add the potatoes,
another layer of compost/straw. Then, as the potatoes grow, keep
adding mulch/compost/straw so that about 2" of stalk stays above. The
theory is that the buried stem will produce spuds along its length.
I did this last year and got a decent first layer of potatoes, but
nothing along the stem. I subsequently read that potato type matters.
This seems like such a good idea- vertical growing!