at first, i thought it was too much sun by the south side window.. but now thinking about it, i think they ran out of fertilizer in the soil mix i used. when the weather gets better, i think they will need few drops to help them keep happy till i move them to 1 gal container. i might just mist them. times like this, i wish i had BT cuttings growing. never added fertilizer to cuttings in cup before.

Pete

    This  us only anecdotal, but the same thing happened to me and I started to add a little fertilizer to my water at the suggestion of other forum members. The fertilizer also has some trace minerals in it. They greened up again.

Try a very weak solution of miracle grow,very,very weak.

I use the water from my koi pond. Green algae grow in water, so there is enough nutrition and mineral for tree as well.