Hi all...for the past three years I've planted potatos and each year I had
lots of plant/greenery but very few spuds. Typically the greenery will be up
to 1 meter high and spread out over a 1 metre radius but yeild only one
giant spud and a three or four smaller spuds per plant. The soil is great
and I add compost and steer manure every spring. I mound up around each
plant. The spuds and rest of the veggie garden get a dose of liquid
fertilizer every two weeks. I've planted late maturing Burbank Russets. I am
in North America, Zone 4. I am considering trimming back the plants (as it
encroages other areas of the garden). Any advice you could provide would be
appreciated?

Thanks

ps Any good treatments to prevent potato scabs?