Q.ZZ plant leaves are drying out and getting brown spots
I received a ZZ plant by mail from a reputable company 2 weeks ago. It seemed to be doing well, but I was away this weekend and when I returned home many of the leaves appear to be dried/drying out and many have developed brown spots. I watered it a small amount last week.
Certified GKH Gardening Expert
That looks like a serious fungal infection! Was the soil still wet when you watered it? This will tend to need to dry out pretty well between waterings. This is usually caused by the soil remaining wet for too long. This give the perfect conditions for bacteria and fungus to survive. They are naturally airborne, so you will have to provide an environment that is inhospitable to them. This is pretty far along, but you can attempt to correct the issue.
Mix 1/4 hydrogen peroxide to 3/4 water and water this once. Spray the top with this mixture, and allow to dry again between the next watering. You will only have to do this once, but it may be weeks before you start to see recovery.
https://www.gardeningknowhow.com/houseplants/zz-plant/caring-for-zz-plant.htm
