Potato tower

So I have never tried growing potatoes before. I plan to try growing a variety that are supposedly purple, although the seed potatoes don't look very purple:

But they have good sprouts on them so there is that. 

Here is a 2x2 bed, filled with compost and dirt to a bit below the surface, with a bamboo and mesh cage surrounding three sides. I plan to wall up the fourth side with more mesh as I fill in the dirt and compost around the plants as they grow. 

So I lay my taters in the middle and also a line of peas around the edge (might as well get extra use from the trellis). 

I expect the soil to sink down a bit because I dug a ton of leaves and compost down into it. The plan is for this to be a combination compost pile and bed, I will use yard trimmings and such to hill up around the plants as they grow. So last step is to pile up soil - a couple of inches at the edge over the peas, 3-4 inches over the spuds. 

So - did I do right?