I think my popcorn is ready to harvest! I harvested a couple ears to check. I picked four that looked like they had bug problems. (Most of the crop looks much better.) The four ears look really good to me. I just chopped off the wormy tips. I'm really impressed. The kernels are nice and hard, but the husks are only just starting to dry. I'm hoping get over to the garden today to pick more.
I think I need to let it dry before popping it. I'll try a test kernel soon.
Here's the information I found at U Wisconsin Extension.
All that is required to grow popcorn for home use is adequate space and a little gardening know-how. Maturity is important in variety selection because popcorn that does not reach full maturity before frost will have very poor quality. It is better to plant several short rows side by side than one long row. Also, do not plant sweet corn and popcorn in the same garden. Popcorn requires adequate nitrogen and should be fertilized accordingly.
Harvest popcorn only after the kernels are hard and the husks completely dry. After picking, remove the husks and store the ears in bags that allow air movement so ears can dry. Each week, shell a few kernels and try popping them. When they pop well, shell the remaining ears and store in moisture-proof containers. Because popcorn can become infested with several types of insects, refrigeration is the best long-term storage.
Determining if moisture content is optimum for the best popping volume is a difficult problem. If the popcorn is "chewy" after popping, it is probably still too wet; so allow the kernels to dry some more, popping a sample every couple of days until the flakes are no longer chewy. Popcorn that pops poorly with many unpopped kernels is probably too dry and needs moisture. Start by adding one tablespoon of water to a quart of popcorn, mix well a couple of times that day, then after 2-3 days try popping another sample. Continue this procedure until the popcorn pops well.