Every year I grow spuds in a small garden and every year the plants become huge while I'm left with only a small crop (usually one giant potatoe and four small ones from each plant). It seems like each plant is putting most of its energy into the greenry and not much into the spuds. I'm using Russet Burbank, late maturing seed potatoes. I should get about 40kgs of spuds (according to the seed manufacturer) but am lucky to get 10kgs. The soil is great..add compost and steer manure every year and use a veg fertilizer every two weeks. Any advice would be appreciated.
Phil