Composting worms will not last long in the garden. You may not care about that. They will just end up as fertilizer themselves.
I actually think you should not worry in the first place about there being too many worms. If there is not enough space or food for the worms to increase, they will not reproduce as fast, or some of them will die off.
But since you do have more worms now than you want, let me suggest that instead of throwing them in the yard to fend for themselves you find people to give them to to start their own bins. You can enlist your friends to start composting with worms, or easier yet, just put something on craigslist or freecycle. I posted something on my local freecycle last year and a dozen people responded! I gave each of the first four a quart yogurt container of worms and castings. A couple of others got worms about a month later after mine had a chance to reproduce some more.
It was fun for me, as I met some nice people, and I always like to see more worm composting going on in the world.
mbetts

I thought of putting an ad on craigslist. I do have a neighbor who may be interested..hmmm

Never thought having too many would be a problem but it's summer so if you offered some to a fishermen I bet you could get rid of lots that way.

Fisherman, fisherman? Better give them to a would-be vermicomposter I'd say.

I could never give my worms away for someone to use them as bait!! They are my babies now!!

Funny thing is, when I bought them from a tackle shop, the guy was like "you goin fishin??". And I said "NO!! I wouldn't KILL THEM!! I built a nice cozy home for them!!" HE thought I was nuts and had never heard of vermicomposting. ha.