I’ve had this zz for awhile and I just noticed all the leaves on a couple of stalks are starting to turn yellow. There’s now 3 stalks with all the leaves tips turning yellow. I water it about 4-5 weeks or when the soil is completely dry. Anyone have tips? Also, do I completely cut down the stalks that have all yellow leaves or just cut off the yellow leaves? Or wait for it to fall off.. thanks!