My zz plant was doing okay. Wasn't growing as quickly as other describe despite living outside in a shady but bright part of my deck in NC USA. Should be getting plenty light and is protected from rain. Then this morning I find it like this. Each stem has a soft brown spot at the base and has fallen over. I cut them off and put them in a glass jar of water until I know what to do with the cuttings. I quickly checked the roots and everything looks and smells normal so I put it back in the soil.
The soil is a cactus mix with extra perlite added for drainage. So what could have caused this sudden change? And what is the best way to propagete zz plant cuttings? I have 4 or 5 so I think I may experiment with water propagtion and perlite propagation.
My guess is the soil probably not having the correct nutrients/pH. Other suspect is over watering or not enough drainage, but that's not likely IMO. Maybe repot with adding 50% gardening soil and water sparingly with some rainwater and add some low intensity fertilizer - it should come back with new sprouts.
Best way to propagate is to cut a piece off the root ball with stem and all, as this develops much faster.
Just the stem works too in water, but takes much longer. You leave it in the water and change it regularly until it grows about an inch or two of roots. Then plant it in some proper soil (mix of coco choir and soil worked great for me) and wait about 6 months, watering sparingly, as the root ball develops. Only then will the cutting slowly die off and new leaves will begin to sprout out of the soil. You'll have to be patient though.
Don't forget to use fertilizer every few weeks from spring to fall, but a gentle one, I always use standard vegetable fertilizer in a medium dose