Yellow leaves say too much water and when leaves are brown it means not enough water.
Adding too much water will make your plant leaves turn yellow, you probably shouldn't water it as much, or don't put that much water on it when you do water it.
More than likely, too much water.
It probably needs to be fertilized. Good luck!
Check k the soil if its heavily damp ,it might be over-watered or theres not good drainage.
There is to much water. Don't water them for a few days.I know you can't help it if it rains, but only water your garden if you can poke a stick 4-6inches into the soil and no dirt sticks to it. Damp dirt, not dry stuff,
Giving it to much water will make the leaves turn yellow or it could be root bound!
It means that your plant is drying up it should help if you give it some more water though