Chicken wire works, so does wire mesh. You can also purchase fiberglas concrete additives used typically to strengthen concrete for various applications. Available where you purchase concrete.

Not much you can do now about the one that is cracked, however.

Either leave the cracked one alone, as it will be just fine with plants growing down the cracks; or go to Home Depot, purchase some Goop and stick it back together.

You might want to try making the walls a little thicker on a trough that size; might try at least 1.5 to 2 inches. Did you use the fiberglass fibers? Also, there is a latex admix that makes concrete stronger, but I don't think you would need it if you make the sides/bottom thicker.

On the other hand, sometimes they just crack lol

Hypertufa is not as strong as concrete. So under certain stress, weight, it will crack.
Is it possible that someone stepped on one side? If not here are my 2 cents.

If the hypertufa cures proberly, and is thick enough, it will have adequete strength, without reinforcement. Allow it to cure for at least 1 -2 weeks, keeping it moist and covered the entire time.
For larger containers (a little bigger than this one), I have added concrete fibers. I am not sure if ad mix really adds strenght, I have heard conflicting reports.
I mix my tufa --- 1 -1 -1 so that there is at least 1 part portland cement. ( peat and perlite) Not too wet.

Be creative with the container - They make great ( 1/2 ) containers ----- Mike

Here is a link that might be useful: Some pictures to look at and stuff to read.

Never underestimate the power of a broken trough lol

This one was ready to go to a sale when someone ran over it with a truck!

I have broken a favorite bowl made from hypertufa, and I managed to repair it and it has held up all year.

My bowl shattered into several pieces, but I put them together like a jigsaw puzzle using Quikrete Concrete Repair in a Tube. I emptied all the soil and let it set several days in the garage to make sure it was dry. Then I applied the stuff into all the edges and put them together as best I could.

I have a streak through the bowl now in several spots. But I loved it so much, it was worth it. Now I like it even more since I read about kintsugi philosophy. Of course I wasn't using silver or gold, but the philosophy of something becoming more valuable because it was shattered and put back together meant a lot to me at that time. Sometimes from a great hurt or injury, we get a life lesson . We all have our scars.

I still have my bowl and it is just fine! Hope you can repair yours.

The pots repair quite nicely with any number of products; I use Goop; it holds well and is clear. Pots are quite lovely used broken if there is enough left of the original pot to plant in with plants tumbling out over what looks like an ancient ruin.

If your setting them on the ground try and place a layer of peastone under the pot, it's pretty much self leveling -3" to 4" should do the trick