I have searched and read the forums, but have not found this specific question with these variables.

I am a container gardener and this year we attempted potatoes in 7 gallon containers. I got Purple Majestys and Red Norland from my local box store. The directions said plant them 8" deep then when they are 7-8" tall, hill them. I did all that and about 2.5 months after planting the plant the leaves yellowed and fell back, with no flowers every growing just leaves, and I pulled the potatoes. I had a yield of about 3-4 potatoes per plant. The purples were kind of small and the reds were an ok size.

So now is round two, but I want to plant them in the ground for a greater yield. I just learned about hilling, and how if you keep hilling them you'll get more potatoes.

Could not doing this step (elaborately with cages and mulch etc.) be why I only ended up with 3-4 per plant?

Is hilling also required/needed for this plants?

Will multiple hillings extend that 2.5 month time I experienced before?

Lastly, can I save up and use grass clippings, or is there a better alternative? (our home stores seem to only sell generic stuff, not many specialty items)

I am basically just trying to plan what to do, to do it right this time.

Thanks