Jeanette,
I never heard of corn cob jelly either, sounds interesting. Our corn here (Buffalo N.Y. area) is only ankle high.
I usually don't start canning until september.
I grow a huge garden and usually put up 75-100 jars each year, tomato sauce, jalapeno jelly, beet conserve, pikeled green beans, two years ago I started making ketchup, there's nothing like homemade ketchup!
Kevin