From the parallel universe department:
On a UK garden forum, a poster named "plainleaf" wrote about his project in which he optimistically expected that he would harvest 150 lbs. of spuds for each seed potato. It appears that it is nothing more than the trench method except it involves with starting with giant, mutant potatoes, the use of a backhoe and two tons of cow manure.
This is my understanding of the method: Get your backhoe from your garden shed. Dig a hole 4 feet into the earth and big enough to bury a Buick. (Have your blasting equipment handy just in case you hit bedrock.) Have a friend lower you into the hole with a rope and carefully roll the mutant seed spud down a ramp (or use the backhoe to lower it in a sling to the bottom of the pit.) Center the "seed" in the middle of the hole and cover with 6" of compost. Then keep adding compost to cover the growing vines until they reach the surface of the earth and continue until it resembles an ancient burial mound, about 4 feet above ground.
Then in the fall, simply get your backhoe out and harvest!
Perhaps Grid's method is similar to the "plainleaf" method?
Unfortunately, the thread ended suddenly with "plainleaf" inexplicably changing his name to "plainleaf2" and there was no follow-up as to whether he achieved his goal of 150lbs per plant. Just as well the thread ended, I guess. The members there seemed very irritated by his mere presence on the boards, continually changing his name , etc.
Here's a link to the
Allotments 4 All thread.Wayne