Singed/Yorick > Garen

Thormail an health

One does not "Beat" Garen...You try to keep up.

I've found that the key to beating a Garen in lane is to keep him in combat so that his passive doesn't start up and heal him. Kinda like the key to beating Cho'Gath is to keep him off the minions.

The other thing is to wait for him to use his spin on a minion wave (which he will probably do at some point) and then charge him as soon as he does. Actually this applies to any top lane matchup - make or wait for them to whiff a major damaging skill and then charge them while it's on cooldown. Do what you can then get back out.

I personally choose to use Riven against Garen since she can win trades with him pretty handily, plus since she is also manaless she can engage him repeatedly to prevent his passive from proc'ing. Her Q's third hit has the nice bonus of knocking Garen back out of his spin range too.

From what you've said, I think your primary problem in this matchup (since you said you played Riven) is that you were too passive and allowed him to engage on his own terms.

Garen ability to sustain in lane and deal incredible amounts of damage early, means that you are forced into either
picking a meele champion with a range harass that is spamable,
a champion with some sort of sustain that can at least match Garen's,
or have your jungler aggressivily gank him early.
There isn't other ways to beat him with a meele champion.
Range, well, they have the abilit to kite him to some extent thanks to Garen lacking any sort of hard dash and slow or hard cc to force them to stay in range.

I played today against a garen as renekton, I just stood outtrading him, kept farming, he started being agressive, ran away, wasted skills on minions, I dealt a lot more damage than he did.As riven, your stun animation is faster than his autiattack, wait for him to come, stun him, run, wait for him to silence minions, be agressive.

bruiser fizz. both times I picked him recently I faced a garen and was 2-3 kills up on him by midgame. once he had sunfire and warmogs I couldn't 1v1 him much but by that point we were roaming and teamfighting anyways so it didn't matter much.

I moreso asked how to not get raped by him instead of how to flat out counter, smartass.

vlad is a great counter to garen i find, if u can stay away from his silence

And how are you going to kite anyone as Darius? With youre ranged slow/stun? With your dash move to create distance? Oh wait, oh wait you don't have those. If you can Q Garen then there's no way you'll get away from his Q's speedup. Now as long as you still have your E you can grab him after he's done spinning and trying to run and end up winning the trade if not killing him outright so its not like he hard counters you. But don't try to say anything along the lines of kiting someone as Darius cause that's just not going to happen