I grew two crops of corn is the same plot many years ago. The variety I selected was Golden Bantam because it will germinate in cold soil and it matures rather quickly. I applied horse manure both times. For the second crop I remember adding two inches of it.

Last year I grew Red Norland potatoes and after harvesting the new potatoes I planted Canela Russet in the same spot. I didn't refertilize for the 2nd planting. The resulting potatoes were much the same as those I had planted in the spring.

Thanks John for mentioning your past results. Actually, potatoes and corn are two of the crops I was thinking about trying doubling up on. My growing season is just about long enough for two crops after considering the extra time needed for fall crops. I've read double cropping can't be done so it's nice to hear from someone who's had success in the past. Of course, the website I read that from was also selling software to determine how to rotate crops so they kinda had a motive.

If double cropping can't be done, then somebody needs to tell Monty Don of Gardener's World!! He double crops his veggie garden all the time and with documented, onscreen success!!

I've seen him do it with greens of all kinds, radishes, carrots, peas and potatoes. Not with corn....growing season is too short for double cropping of many warm season crops.

I do it every year with Strike Peas. Days to Maturity is about 47 days. I plant in Spring, then another vegetable in summer, then peas again in Sept.