you tell the Cub leader (usually an 'Akela' here in Canada) of your concerns. He/She will go out of her/his way to help your son. There will likely be several groups in your local area, so go visiting and ask to observe. They won't mind a prospective parent sitting on the sidelines, especially if you tell them why you are investigating. Cub leaders are 'kid people', usually, and will feel for your son and want to help. Plus, they'll have lots of skills to help!
You can 'facilitate' friendship making...at any group activity, not just cubs. Hang out a bit when dropping off and picking up, make friends with the other moms and dads...get involved! Chances are you can pick some kids who seem likely and help smooth the way for some friendships. You could, after a time, arrange playdates outside the activity...this is easier when you know the parents, instead of waiting for the kids to have the idea.
Do choose 'activity' based playdates to start, ie trips to a local park with you and dad or to areas of local interest...maple sugar bush, ice skating, etc. or movies or whatever if you can afford it. 5th graders still enjoy time with mom and dad, mostly, and that way you can see if things are progressing well -- plus you can coach your son if he does need help. Possibly he won't, if you can find the right kids -- all it takes is the opportunity. Making friends is just like dating, IMO...the 'getting to know you' is easier when you don't have to make too much conversation, and you are enjoying a mutally agreeable activity! Then, as you find kids who are compatible, you can concentrate on those...and then if all is well you can gradually withdraw and let them 'just play'. HINT -- don't pick the most popular kids that 'everyone' is after -- look for kids who seem similar in interests, etc. to your son.
OF COURSE you are emotional! This is your 'heart' the 5th grade world is 'rejecting' -- but there is lots you can do to help! Hope you will come back for advice if you need it -- LOTS of us around here have done this sort of thing...I became a Beaver Leader and am now a Cub leader for similar reasons -- though my son is now on to Scouts and I am staying at Cubs since I love the age group and he NOW needs 'less mom' to improve his independence and learn to interact with other adults without my influence.
My son has a few true-blue and compatible friends and is managing very well in Gr. 6, though he is still by nature 'slow to warm up' and a bit of a loner/outsider...we started very early, but that does not mean you can't help your son acquire a few good friends. And it doesn't hurt to learn early that the 'popular crowd' are not the ONLY crowd! Just cuz those guys think he is 'dorky' doesn't mean EVERYONE does or will -- he needs to learn to actively seek out those who are most likely to befriend him -- for my son, that would NOT be guys who judge what he thinks is 'cool' as 'dorky', or kids that tease and put down others (except buddies who do it gently in fun, of course -- these are the years to learn the difference!)
Sorry this is so long, but I feel for your son and I LOVE to help kids like this in my pack! If the kids participate in all activities, especially camps and day trips outside the meetings, it usually happens without much effort. Even if you are not interested in doing the playdate stuff, just having organized activities with compatible people makes us less lonely -- ergo, we HAVE friends!
Feel free to ask for specific advice as time goes on -- and share all this with your son. "hey, honey, maybe we need to broaden your chances for making friends -- those kids at school aren't the only kids in the world. Now, how about...(swim club, cubs, theatre group, etc). Making friends is a SKILL -- some of us have to learn it, and that is no shame. Take heart, and take action...Merry Xmas and Happy New Year!
