ZZ Plant Diagnosticians Needed! One shoot @ a time, leaves yellow, usually from the tips to the stem, then the stem goes soft and I cut it away. It has been small young stems until now and now it has struck a large older stem. I have a 24 high ZZ plant, bought about 1 year ago from a reputable greenhouse/nursery in the area. It seems it is always putting out new healthy looking shoots, but one by one I notice another otherwise has been healthy shoot begin to look a pale green, the leaves yellow, but only on that shoot and gradually the shoot begins to look shriveled and soften a bit. It started last summer so I put it outside to see if it needed more light. It seemed to not make a difference and continues. I took it out of its plastic pot ( 8 Bottom Width X 9.75 Top Width X 8.75 Ht.) it came in. It had a large root structure from the tubers, some fit tightly against the plastic perimeter of the pot. I gently took the soil away and trimmed the roots of a few (3) that seemed mushy at the end of the tip, and removed others that seemed like they were a wet flat fleshy thread that may have been a root and slowly seemed to decompose. A better description would be like a limp flat off-white intestinal casing and these seemed to just pull out of the root structure with ease. One large tuber seemingly connected to the now yellowing large stem seemed to be softer, shriveled and not looking as robust as the others. The original soil it came in was a mixture of soil, pearlite and much bark. As for watering, I hardly water it. I was told to water lightly once every 7-8 weeks. I took the plant to the place I purchased it and they said, maybe re-pot it, maybe a little bigger pot, and maybe new soil. I found them less than helpful. Any suggestions?
ZZ is a succulent aroid (Philodendron family). Whoever told you to water, lightly, once every 7 - 8 weeks was wrong. When you water, water thoroughly and then let the soil become fairly dry before you water thoroughly, again. ZZ will tolerate low light, but will grow much better in high (good) light. ZZ likes a moisture-retentive soil that drains well (I know, this is sort of a contradiction) and that's why there was so much bark in the original soil mixture. I would use a good commercial potting soil mix and mix the potting soil approx. 50/50 with perilite. The perilite will give good drainage without making the soil mix heavy. Don't use/add sand - unless you want to make concrete. After re-potting, keep the plant in a little lower-light spot for a month or so and then slowly move the plant to a higher light position. This should make your plant happy. Don't worry if your plant loses leaves every now and then; no plant retains all of its leaves forever. It is natural for your plant to occasionally lose foliage. Good luck, Mike
Just a bit of a correction. Zamioculcas zamiifolia is an aroid, and so is a Philodendron. But Zamioculcas zamiifolia is not in the Philodendron family. This is a very distant relative. Philodendron sp. Anthurium sp., and many others are in the group of plants known as Araceae. The short name for Araceae is simply aroids. But these species are very different. All Philodendron species are found in Central America, Mexico, or South America with a few in the West Indies. Zamioculcas zamiifolia is from West Africa. Their growth and care are not even similar. Most aroids are rain forest species while Zamioculcas zamiifolia comes from arid plains. Other than that, the majority of the advice above is quite good. Just make sure and plant this aroid in quick draining soil. It grows in sandy soil in Africa and receives a lot of water in the summer but little in the winter. Don't plant it in muddy soil and don't allow the roots to stay wet.
