Root bound maybe? Just a guess. Maybe get some more light and see if that helps if not I'd transplant it into a bigger pot. Good luck
He just recently started turning light green like the tallest ones in the middle. He used to look like the one o the far bottom right. Now he's starting to crack a bit on the one on the left. I <3 hobbit weed
Hi emilystrange, That looks like mother-in-laws tongue. I'd move it to a smaller pot with a drainage hole in the bottom, two to three inches in diameter larger than the root ball. Use a loose, well draining potting soil, they don't like wet feet. Let the soil dry out between waterings. As far as 'light' needs, MILT prefer high light, but does adjust to low light growing conditions just fine. The growth rate will be slower in lower light levels. Good luck.
If that doesn't help the yellowing u can hit it with some N just to revive it and give it some color. Just like MJ plants they need food too