ZZ plants are well-known for their tolerance to low light conditions – but that does not mean they will grow happily or optimally when completely deprived of sunlight.
Like many houseplants, ZZs do better when exposed to 12 hours of indirect or filtered sunlight daily. Too much sunlight can burn their leaves, while too little light can cause stunted growth.
If you have just started growing a ZZ plant, you will need to understand the best lighting conditions to keep it in tip-top shape. Read on to learn about the ideal light range for your ZZ, as well as the ill effects of exposing your plants to more or less light.
Do ZZ plants require sunlight?
The answer to this question is quite obvious – all plants, including ZZs, need sunlight to survive.
However, for most novice gardeners, it may be easy to assume that ZZ plants will do well without any sunlight because they are known to be forgiving and can tolerate neglect. However, this does not mean that ZZs are indestructible – they can only survive so long without proper care and love!
ZZ plants rely on sunlight to create their own “food.” This vital process is known as photosynthesis. Aside from light, they also need oxygen, water, and soil nutrients in order to grow and flourish. Once the plants have harvested the sun’s energy and performed their vital cellular functions, they produce oxygen as a byproduct which benefits other living organisms, including us, on earth.
A light-deprived ZZ plant will struggle to carry on these functions, regardless of the abundance of water, oxygen, and nutrients in the soil. Without the sun, it will stop growing to conserve its remaining energy and continue surviving. With extended periods of low light, it will eventually reach its limits and die.
How much light do ZZ plants need?
There is a huge difference between a plant growing well and a plant barely surviving.
While it is true that ZZ plants can survive longer than most without sunlight, they can still suffer the consequences that manifest through symptoms such as drooping, legginess, and defoliation. Your plant might be surviving, but it will look sick and unattractive!
If you want your plant to flourish and reach its full potential, you should not deprive it of sunlight. But how much sunlight do ZZ plants actually need to grow healthily? First, you need to know about their natural habitat to help you understand their needs.
ZZ plants, or Zamioculcas zamiifolia, originated from the forests of East Africa. This area is located at the equator, where the daily sunlight totals around 12 hours. ZZ plants inhabit the canopy layer of the forest, where they can enjoy hours of filtered sunlight. Thus, to ensure proper growth in your home, you need to place your ZZ in a spot that gets as close to 12 hours of indirect sunlight as possible.
Unfortunately, not all ZZ owners live in areas with such long days, especially during the winter season. This makes it more challenging to provide their plants with the requisite hours of indirect sunlight. But remember that ZZ plants can survive on less than 12 hours of light – as mentioned before, they are extremely resilient and can survive a certain time in less-than-ideal lighting.
The only problem with light-deprived ZZ plants is that they will not look great overall. Their leaves will start to go pale or yellow because they are not able to produce enough chlorophyll. Over time, they will also become leggy and sparse as their stems stretch out in search of new light sources. As the plant reaches its light tolerance limit, it will eventually droop, weaken, and die.
Summertime is the ideal season to allow your ZZ plant to enjoy indirect sunlight for 12 hours (or even more). Or, if you do not have the perfect spot for indirect sunlight, you can use artificial grow lights instead (more on this later).
Direct versus indirect sunlight – what is the difference?
We have repeatedly mentioned the importance of indirect sunlight for our indoor plants, as well as the negative effects of exposing them to direct sunlight. But what is the difference between direct and indirect sunlight?
Direct sunlight refers to the unfiltered path of light from the sun to your plant. You usually get this type of light through south- or southwest-facing windows. Since this light is very intense for most plants, it can cause wilting and scorching of the leaves. Your ZZ plant will not be able to tolerate the heat from direct sunlight.
On the flip side, indirect sunlight is sunlight that passes or reflects through a medium before reaching your plant. This could be found in many areas in your home where there is bright light without the direct heat of the sun hitting your plant’s foliage. ZZ plants do better in filtered sunlight since it allows them to perform photosynthesis without harming their leaves. Windows facing east are usually a good source of indirect sunlight for plants.
If you are not sure about the type of light your ZZ plant is receiving, simply place your hand between the light source and your plant. If your hand makes a shadow or you can feel the heat, then the light is too direct. In that case, move your plant to another spot with less direct light.
Can ZZ plants live in low light?
As mentioned, ZZ plants can tolerate low light conditions, but only for a limited period. Without the sun, your plant cannot produce its own food and energy to survive.
So, how do you know if your ZZ plant is light-deprived? What are the symptoms?
If you suspect your plant is are not getting enough sunlight, look out for these signs:
- Your plant looks leggy or stretched-out, and bare. This condition is called etiolation.
- The leaves are smaller and have bigger gaps between them.
- The plant seems to lean more to one side, rather than growing symmetrically. This is because it is trying to capture as much light as possible by leaning toward a brighter spot.
- The stem becomes soft and droopy.
- The leaves look pale instead of dark green.
Can ZZ plants handle bright light?
As mentioned previously, plants that are exposed to direct, unfiltered sunlight will likely suffer from leaf burn. That is because most indoor plants like ZZs are sensitive to the sun’s heat. Elevated temperatures can increase the plants’ transpiration rate, causing them to lose moisture from their leaves faster than usual. This can result in brown, crispy leaves, especially the top ones that are most exposed to the sunlight. Unfortunately, this injury is irreversible – once the leaves are damaged, you can only trim them off and give your plant the necessary care to encourage new growth.
Choosing the best location for your ZZ
Most growers recommend placing your ZZ plant near an east-facing window, because this is the perfect spot for indirect sunlight. Try to make sure that your plant gets about 12 hours of bright, filtered light each day, especially during the growing season.
It is also recommended that you place your plant in an area where there are no temperature fluctuations or drafts. ZZ plants prefer temperatures between 60 and 75 degrees Fahrenheit – anything below or above this range can cause plant stress. Do not place your plant near a window with hot, direct sunlight, and during the colder months, keep it away from open doors and windows.
Can you keep ZZ plants in a room with no windows?
For plant parents who do not have enough windows for their ZZ plants, there is another option, which is artificial grow lights.
Grow lights are designed with light bulbs that mimic sunlight, so if you cannot find the perfect spot for your ZZ, or if there is too little sunlight during the winter season, then these artificial lights should suffice to keep your plant happy and thriving. Grow lights like GooingTop provide the full spectrum of sunlight at 6000 Kelvin, which is ideal for ZZ plants. Of course, there are other LED grow lights available, but make sure they fall within the range of 3500 to 6500 Kelvin. Otherwise, you will not get the best growing results.
You also need to make sure that the plant’s foliage is about 18 inches away from the artificial light source. If you set it too close, it might burn the leaves, just like exposing the plant to direct sunlight. Aim for at least 12 hours of light exposure, but you can also increase it to 14 or 16 hours.
Can you keep ZZ plants outside during summer?
If you want to give your plant a little boost of energy, you can place it outside during spring and summer. Just keep in mind that the same rules apply as if it were indoors.
First, make sure your plant sits in a shaded area – as mentioned, ZZs cannot tolerate bright, direct sunlight. For example, you could place it on a covered patio, near other, taller plants, or on a porch with an overhang. Make sure that the outdoor temperature is within the plant’s comfort zone (which is 65 to 75 degrees Fahrenheit), and watch out for any sudden temperature drops at night! If it is too cold, then you should avoid placing your plant outdoors.
It is also important to gradually acclimatize your plant to the outdoors to prevent environmental shock. For example, you can put it outside for a couple of hours each day, gradually increasing the time until eventually it can stay outside throughout the day.
Lastly, plants can dry out more easily when kept outside, so make sure to adjust your watering schedule accordingly. Water your plant as soon as the topsoil becomes dry to prevent underwatering issues.
Many growers fall in love with ZZ plants because of their beautiful foliage and great resilience to sub-optimal growing conditions. However, even ZZ plants have their limits, and this applies to low light levels, too. If you do not provide your plant with sufficient light, eventually that attractive, dark-green foliage you once admired will become lifeless and sad.
Thankfully, these hardy plants can quickly recover as soon as you spot and correct the problem. Move your plant to a spot that gets lots of bright, indirect sunlight, or get an artificial grow light, and it is sure to reward you with healthy and vibrant growth!
Image: istockphoto.com / Zaikina