the yield was pathetic!!! I grew several varieties and none of them yielded more than a few potatoes! I need to blame this on something LOL! The weathers fault? Now I have to BUY potatoes all Winter UGH! on a related note, my onions were also unusually small.
Definately temp. related, I plant potatoes around St. Patricks day. It mite freeze after that but the tops usually come back and keep producing tubers. Your summer was hotter then ours and I would NEVER even consider planting potatoes in the summer here. At least your summers aren't usually that hot!
Potatoes need fertilizer, consistent water and hilling up. I hill mine about 3x a season, and leave them until the vines are dead down. I also had pick potato beetles off the plants and drown them in a jug of water with a lid on it. (they stink) They will sap the plant of strength, and eat off the potato blooms.
I had never grown potatoes until a couple of years ago. The first year ok but not a bunch. One of my buddies, who raises a lot of potatoes, to till in a lot of 0-20-20 fertilizer before planting and then side dress with 8-8-8 after they are growing good. Made a bunch.
I agree about tilling in 0-20-20 fertilizer before planting potatoes, then side-dress with something similar to 8-8-8 when they're half grown.
I till in the fertilizer so the ground is good and soft, then I cut a trench only about 2" deep with the corner of a hoe. I plant my potatoes in the trench, cover them over, then walk the length of the rows to pack the soil down. The same day I plant I run soaker hoses on top of the ground right beside those trenches, as potatoes really do need even watering.
When the plants are 2 or 3 inches high, I cover the rows with about 6" of straw then spinkle soil loosely on top of the straw. After that, I hill them up with soil only but the rows have that soft center of straw so the 'taters grow big and are easy to dig. Since the straw is in contact with my soaker hoses, the straw stays damp from my running the soaker hoses every couple of days - and that helps maintain an even moisture level at the roots of the plants.
I'm just one state over from Illinois, and I'd never try to grow potatoes through our hot summers. I plant 'em in March, harvest 'em in May or early June, and then re-fertilize, till, and plant sweet corn on the same patch of ground.