Kean may be a bit too heavy duty: I believe those are graduate-level classes that are opened to non-matriculated students.
I think all state universities give seniors the opportunity to audit classes with the permission of the professor (an email will suffice). You don't get to take the exams but you can take the class and participate. I have had several participate in my classes.
Master Gardener Classes:
http://mgessex.org/become-a-master-gardener/
Duke Farms Classes
http://dukefarms.org/publicprograms
Scherman Hoffman Sanctuary Workshops
http://community.njaudubon.org/schermanhoffmancalendar
I just saw in the Sunday paper that Boscovs in woodbridge is offering free seminars...I didn't pay much attention to what they were.
Looking for fun/stimulating classes for retirees at a location no more than 30 minutes from this area. Daytime okay. Something beyond the local high school adult school offerings. (I know Rutgers/Highland Park has some, but it's too far.) Any personal recommendations?