Suoer Sweets can become almost inedible when cross pollinated with normal corn. The texture becomes very rubbery. It is a type that requires absolute isolation. The other types are not so picky. Yes if you plant a white and a yellow together you will get bicolor. If both your 90 and your 72 are the same color and neither is a super sweet you should be ok. Of course a 90 day corn will be a much larger plant and in a dense planting may crowd out the smaller plants.

Agree with farmer.

I question planting corn now. I planted my last on July 6.

Thanks farmerdill -- I will stick with the corn I know is not super sweet.

wayne -- oh no. I consider you THE corn expert, and you think it's too late? We can get frost as early as early September and as late as late October, so I thought I may well be okay. If nothing else, it seems I would need more corn to insure good pollination because the rows are so sparse. Maybe worth the gamble?

Thanks, Dave. I do actually plant intensively -- about an inch apart -- and thin. But the soil was wet, with no dry in sight, so I took the risk and planted anyway. I planted the 72 day today. Will see how it all turns out. I'll get new seed for next year anyway, in case the seed was part of the issue.

Report on results of planting 72 day corn in late July -- I ended up with baby corn!!! Very interesting -- even the cob is tender and sweet.

Chinese food anyone?

It's delicious, so not a 100% fail.

But will plant newer seed next year, and hope for much better germination.

My last planting on July 6th was extremely robust and came in early with many stalks with 2 GOOD ears... better than average. This year a later planting might have made some fair corn.