ZZ plants stems can bend if the plant is overwatered which can cause root and stem damage causing them to lose strength. Stems can also bend if the plant is getting too much light, not enough nutrients, due to the stress of transplant or rhizome damage.
This article will explore why ZZ plant stems do not grow straight and what you can do to straighten them.
Why ZZ plants do not grow straight
Here are the top causes of bending stems on ZZ plant. This is a common problem and one that I managed to solve for my ZZ plant
1. Overwatering
Overwatering is the top cause of bending stems on ZZ plants. Too much water can cause the ZZ plant to absorb too much water causing damage to the rhizome and root rot. When the rhizomes and roots rot, the plant will no longer be able to absorb nutrients and it can cause damage to the stem.
You can often notice black or brown spots on the stem to pair with overwatering. The stem damage causes it to bend and the long stems will no longer grow straight.
To solve this problem, reduce your watering schedule to once every 4 weeks. If the soil has become very wet and soggy it can be best to repot the plant into new soil. Allow the water to drain through the bottom of the pot before putting it back on the pot tray or outer pot.
2. Underwatering
Underwatering is rare but it can cause stems on ZZ plants to bend. While ZZ plants are drought hardy if they are left for longer than 4 weeks without extra water they can dry out too much and the plant can suffer damage.
Underwatering will usually be paired with yellowing and browning leaves. Smaller stems are usually affected first and the leaf edges will start to dry off.
3. Light conditions
ZZ plants are sensitive to light. If the plant is placed in direct sunlight the stems can bend over away from the sun to protect itself. If the plant is placed in a very dark position it equally can send its stems over on an angle towards any small amounts of lights.
The perfect light conditions for ZZ plants is fully protected from direct sun but with some indirect light. If you notice your ZZ plant sending stems in the direction of the light, move it out to a brighter position to help to straighten the stems.
4. Stress of transplant
ZZ plants can suffer stress after they have been moved into a new pot. While it is important to repot your ZZ plant every 2-3 years. If you lift and divide your ZZ plant the stems can bend over after you have moved it. Sometimes the root disturbance or extra water can cause the plant to temporarily suffer.
To fix this problem simply allow the plant some time to recover. Water the plant in well but wait for 4 weeks before watering again.
5. Nutrient imbalance
A lack or too much of any one nutrient can cause damage to the ZZ plant. If the leaves appear yellow with green veins, this is a sign that the plant is lacking iron. A lack of nitrogen can also causes yellowing leaves, soft stems and they may bend as a result.
To keep ZZ plants happy it is important to regularly fertilize them to avoid any deficiencies. I like to give them a teaspoon of indoor plant food in spring and fall and this gives the plant all the nutrients it needs for the year.
ZZ plants are not particularly hungry plants but a regular feed of indoor plant food will keep them happy and help them to grow strong straight stems.
How to straighten ZZ plant stems
Here is my favorite method to straighten ZZ plant stems. This is an easy way to prop up the stems until they strengthen up and stand straight.
Twist Ties
The first way I like to straighten ZZ plant stems is to use basic twist ties. When I repot my ZZ plants I like to use twist ties to hold the stems up. Often when you replant ZZ rhizomes the stems will flop over. This can happen just because there is more room in the pot and they have not settled into the soil.
After repotting my ZZ plant I used twist ties to hold the stems together on the bottom. I like to allow the top stems to naturally straighten themselves over time but you can also tie them together if you like them to grow very straight.
You can also use soft pantyhose pieces, plant ties or old cotton t-shirt pieces. Make sure the material is stretchy and is not tied too tightly. This can cause stem damage.
Take the ties off after around 2-3 weeks and your stems should stand straight on their own.
Popsicle sticks, straws or skewers
Another way to hold up ZZ plant stems is to use splints. Use popsicle sticks, bamboo straws, skewers or even chopsticks.
Tie two chopsticks alongside the stems to hold them up straight. Use ties or very stretchy rubber bands to hold the splints along the stem. I have done this with a newly transplanted ZZ plant. This can fix a bent or stem or hold up the plant temporarily while it settles into its new pot.
Why is my ZZ plant not growing straight? | Summary
Stems on ZZ plants will not grow straight if they are lacking nutrients, water and are placed in a space that is too dark. Overwatering is also a common cause of bending stems on ZZ plants. They can become brittle, damaged and can bend over. Support bent stems as the plant recovers by using splints and remove them after around 3 weeks.
Happy growing.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.