I certainly wouldn't plant them any closer than 10". If you try to cram too many plants in there, they won't do well and may not make ears. Even at that spacing, be sure you are really on the ball with watering -- tightly packed plants and drought are a recipe for failure. Both of the kinds you are planning are normal, open pollinated corns, so they don't have the issue of making "flinty" kernels like some hybrids can when different classes are planted together. In theory, if you were to plant them about 3 weeks apart, you probably could do what you are planning and get relatively pure seed from each strain. However, I don't know if it works differently in Arizona due to climate, but here in Michigan, it seems like staggered plantings all seem to mature at about the same time anyway -- probably a function of our cool springs where the early plantings just sit, and then all start to grow when it warms up. With the planting density, I don't think you should have any problems with pollination, but OTOH, with such a small bed, it sure wouldn't be very hard to do some hand pollination, so it might be worth the few minutes work just as an insurance policy.

oldroser, I never said corn was not wind pollinated. I was only stating that the tip of corn cobs where the kernels are undeveloped is more often a result of lack of sufficient watering thru to the end of cob development rather than lack of pollination. Lack of pollination results in cobs that would look like this: *wink* Severe heat and moisture stress during the first seven to ten days after pollination will cause kernels at the tip of the ear to abort. shellva will have to make a personal decision as to whether or not there are enough stalks close enough together before taking any out.

"I am using intensive planting this year for the first time with my corn. They are planted 6 inches apart with rows 12 inches apart. This is a block of 4 rows wide. The first planting of 4 feet x 8 feet was June 9. The 2nd planting was a week later and the 3rd planting was a week after that. The first planting has tassels on all stalks but still no ears. ???? The corn gets at least 8 hours of direct sun." How would you harvest that corn if it produced any ears? Silver Queen will produce lots of leaves. You would not be able to walk between rows of mature corn planted 12 inches apart! I grew Silver Queen for years, but switched varieties this year to varieties more resistant to smut. To Silver King for my late white corn. I plant my corn in rows spaced 8", but my rows are 3' apart! I don't see how you can cultivate, fertilize, or harvest corn planted in rows 12" apart.

The central ones seem pretty normal. I picked and opened one bunch, just out of curiosity. The secondary ears seem to be fully pollinated, but are behind the central ear maturity-wise. We'll see if they're worth the effort to process once they're ready to harvest, I suppose. When it's time to pick, I'll try to do a tally of all the strange ones. Fruitnut, spacing is 12" between plants and 24" between rows. :)