I plant potatoes twice a year. Plant in spring (late March) for a Summer harvest and plant again in Summer (late July to early August) for an Autumn harvest. Typically I get about 2.5 kg of potatoes per square meter each time. For a yearly net of 5 kg per square meter. Which I think is not too bad.

I normally plant red potatoes as they seem to give the largest harvest. But I also planted some yellow potatoes this summer just to see what I would get. And the results were not too bad. But, yes, the yield was a bit less than the red potatoes.