Zamioculcas is such a resilient plant that you won’t have to visit this page very often…
Single stem drying out – normal
Stems falling over – lack of light
Drops on leaf tips – guttation
Yellow – overwatering or chlorosis
Curly leaves – scale or mealybugs, rarely spider mite
So just in case, here are the main problems you might meet when caring for your ZZ plant!
ZZ plant turning yellow
If the entire ZZ plant is yellow, it may be due to:
- Root rot – due to overwatering and insufficient drainage. Most common cause of yellowing. Water only when the soil is dry. Check that the pot has a draining hole. Throw out water that collects in the saucer under the ZZ plant. Repot with one-third river sand added to the mix. Cold water or growing outdoors in cold weather makes this much worse.
- Lacking nutrients – Yellowing is a symptom of chlorosis, typical of nutrient deficiencies. Usually, parts of leaves along veins stay green longer. Add fertilizer for leaf plants once a fortnight during the growing season.
- Rootbound – the pot is too small and roots circle around the inside. The plant is strangling itself. Pull out from the pot, untangle the roots, cut the longest ones. The clump shouldn’t have any roots extending out more than an inch (3 cm). Repot to a slightly larger pot.
The last possibility is when a new frond or leaf starts growing that is yellow, white or variegated. This is rare. It is a kind of mutation that occurs naturally, like the black ZZ raven.
Usually these are considered valuable and you will surely find amateurs! Try to propagate it when it has grown a bit more.
No new leaves on ZZ plant
It’s hard to kill a ZZ plant, but if there isn’t much light, it won’t grow very much. Lack of light is the main cause of slow growth. Find a place in the house that is a little more exposed.
- Winter has shorter days: this causes the ZZ plant to go nearly dormant.
If you’re quite sure your plant is getting enough light, then check on watering and temperature swings. These are also known to block ZZ plant from sending out new shoots.
Single dried-out stem
- Best is to let them be: the process of yellowing and drying up lets the plant recover nutrients.
- It’s also fine to remove them to make your ZZ plant look nicer.
This is a normal step in the ZZ plant’s life. Stems last for up to a year. In very favorable environments, a stem can even survive for 2 years. However, as time passes, the plant sends new shoots out. Older stems are less efficient and they wilt away. The yellowing is a sign that nutrients are being brought back into the roots, a form of recycling.
Only cut the stem when it’s fully dried out if you want to help your plant grow more and faster.
It’s also ok to cut it when not fully dry, the plant won’t complain. After all, it is an ornamental houseplant that has the duty to look good!
ZZ plant leaves falling over
More often than not, ZZ plant fronds start drooping down. ZZ stems fall over. The long petioles which carry the leaflets don’t stand upright anymore and fan out.
- The major cause of ZZ plant bending down is lack of light. When a ZZ plant grows in the wild, it grows best in shade and forest underbrush. It sends fronds and leaves in every direction to harvest what little light filters down to the ground.
- This is a natural and normal.
- When sold in flower shops, they usually stand up tall. This is because they’re lit from above and grown in a crowded growing table. As for trees in a forest, these crowded conditions force the ZZ plant to grow straight up.
What can you do to make your ZZ plant grow straight again?
- Rotate the plant to a spot that gets lots of light from above in the house for at least part of the year.
- Put other plants that grow thick and straight near it, like Sansevieria, Spathiphyllum or colorful Croton (among other indoor plants).
- Alternatively, you can simply find a nice-looking stake (like a piece of bamboo) and loosely tether your ZZ leaves to it.
Another possible cause is that the pot is too small. Repot into a larger pot.
ZZ plant has drops of sap on leaves
This occurs in perfectly healthy plants. Their powerful root system keeps pumping water up to the plants. To release pressure, small pores open on leaves. Excess water leaches out and gathers at the tip.
Also, unneeded nutrients and, eventually, debris from bacteria or dead cells are also evacuated.
If you water with tap water or hard water that has lots of minerals, white spots will appear. Excess minerals are also expelled, and they gather when guttation fluid dries out. In the long term, this can damage the leaves. Indeed, these form corrosive salt mounds. To clean these, simply rinse the plant and wipe it with a soft cloth.
Leaves curling up on a ZZ plant
This is rare, and mostly only happens when pest populations are high. Scale insects and/or spider mites infest leaves and suck sap from it.
They leave tiny webs as proof of their presence. In the case of mealybugs, a small cottony substance appears.
Here is an article on how to deal with scale insects on a ZZ plant.