Plants that need more light often show us using visual indicators. If we know what the red flags of light deficiency are then we can help our plants find the light that they need.
This blog post will tell you 6 of these visual clues to help you better help your plant!
1. Your plant is etiolating or stretching
One way plants cope with insufficient light is by etiolating or rapidly growing their stems to reach for light.
Upright plants that are etiolating will look abnormally tall, sparse, and lanky or leggy.
Vining plants will etiolate by increasing the length between nodes.
Nodes are the spots on a plant where leaves, branches, and/or aerial roots emerge. The space between nodes is called the internode.
The more a plant etiolates, the weaker the plant becomes. If moved to an area with adequate lighting, the plant will begin to grow normally again. However, any etiolated growth from a period of light deficiency will remain.
The photo above shows etiolation in succulents. The plant on the right is etiolating, searching for light. You can see how it is leaning and the distance between leaves on the stem is increasing.
It is particularly easy to notice when looking at the succulent on its left, which appears much healthier. The succulent on the left has much smaller distances between nodes. It’s foliage also looks more firm and bulbous.
Here is another example of etiolation in succulents. The photo on the left shows etiolation, where you can see a pronounced distance between places where leaves emerge. The photo on the right shows a trailing succulent with much more compact, healthy growth.
2. Your plant has stopped growing… or is barely growing
Plants grow using energy and food production made possible by light.
If there isn’t enough light, your plant may use what light it does receive to stay alive rather than to grow.
So if your plant has stopped growing or is barely growing, it may need more light!
New leaf growth that is smaller and/or thinner than normal can also be a sign of light deficiency. This symptom can show that the plant has enough light to grow, but not enough light to produce its healthiest growth.
Try moving your plant to a brighter location to see if your plant can produce healthier growth.
If you just brought your plant home, you should expect your plant to need an adjustment period.
Before becoming your houseplant, it was likely living in the optimal conditions of a greenhouse.
Then your plant was either shipped in the dark directly to you or to the store where you bought it, which can be pretty traumatic – especially if it traveled for a long time.
So even if you are giving your plant enough light, it might take a little time for it to show growth after transitioning to your house. However, if your plant came to you healthy AND it has been an extended period without signs of growth, it might be suffering from a light deficiency.
3. Your plant is leaning toward the light
Plants also cope with light deficiency by severely leaning in the direction of a light source. If it can move more of its foliage near the light source, then it may be able to absorb more light and possibly survive longer.
There is a difference between plants that are not regularly rotated versus a plant that is leaning in an effort to get more light.
Plants that aren’t regularly rotated but are receiving adequate light will grow normally and produce healthy foliage on the side that faces the light. The side that doesn’t face the light will likely stop producing growth over-time, creating a lopsided appearance.
On the other hand, plants that aren’t receiving enough light will push their stems and foliage over toward the light in a desperate attempt to reach it at an abnormal angle for the plant.
To use an analogy to our own hair, it is the difference between someone with short hair allowing their hair to flow naturally versus combing over their hair to one side. The plant is combing its foliage over to one side to reach the light.
4. Your plant takes a long time to use water
One reason your plant’s soil might be wet for long periods of time after watering is that it isn’t getting enough light! A plant needs light to have the energy to use the water you provided as a part of photosynthesis. If it is lacking the amount of light it needs, it will be using the water much more slowly.
Try moving the plant to a brighter location to see if this improves the rate at which your plant uses its water.
If this doesn’t improve the rate at which your plant is using water, you can assess for other potential causes as well.
Other possible causes: Your plant needs more well-draining soil; Your plant needs a pot with better drainage; Your plant needs a pot that doesn’t hold moisture as long; Or perhaps you are watering before the soil has completely dried out. (Each section is linked to my previous posts addressing these topics)
5. Your plant’s leaves are losing color
The green color within your plant’s leaves and stems is made possible by chlorophyll.
Chlorophyll is the pigment present in your plant cells that absorbs light and turns it into energy the plant can use to produce food through photosynthesis.
In parts of a plant where light is present, chlorophyll develops.
One of the most notable examples of this is the way that the roots of an orchid behave. Orchids are epiphytic plants, meaning that they typically grow while clinging to trees, rocks, or other plants.
Since they are rooted to other plants or rocks, their roots are exposed to light so their roots develop chlorophyll just as their leaves and stems do.
However, if their roots are kept in a potted container away from light, their roots will fade in color and turn to white, like the roots of the other plants we keep in the home.
A similar principle can be applied to our houseplants.
If plants are not receiving enough light, the chlorophyll in their cells begins to disappear causing a loss of that rich green color over time.
Unlike the orchids who can survive and thrive with white roots as long as their leaves and stems are receiving enough light, loss of leaf color is a serious problem.
If the plant is not moved to an area with more light, the leaves will eventually yellow and die.
6. If your plant is variegated, the new growth is reverting to green
Variegated plants can also tell you they are not receiving enough light by reverting to green.
This is only true for variegated plants that have unstable, chimeric variegation. Chimeric variegation is a cell mutation and is not consistent throughout the plant (to learn more about variegation check out my post here).
These plants will stop producing their variegation in light deficiency BECAUSE they prioritize survival.
Areas of variegation (non-green areas) are not capable of photosynthesizing so they are not able to produce energy and food for the plant.
You can stop your plant from reverting to green by moving it to an area with more light and removing the part of your plant that is all green.
To summarize, here are some ways to identify whether your plant needs more light:
- The plant is rapidly growing its stem — producing a plant that appears stretched, lanky, and weak
- New leaf growth is smaller than normal/expected
- The plant has stopped growing or is growing extremely slowly
- You notice that the plant isn’t using its water for long periods of time
- Your plant is leaning and stretching toward the light
- Its leaves are losing color
- If variegated, your plant has stopped producing variegation
Using a Light Meter
If you want a product to help you better understand the lighting in your home, I recommend trying an inexpensive light meter.
Light meters can be used to measure the amount of light at various times throughout the day in a spot you want to place a plant at a much more accurate level than our eyes can.
I use the light meter in the photo below (which is linked to Amazon through the affiliate program). It has been really eye-opening for me to assess various spaces in my own home and has completely redefined what I understood as low light and high light.
When I use mine, I set the meter to measure light in footcandles and use the guide below to determine what kinds of plants I can put in each area.
Low Light: 75 to 200 footcandles
Medium Light: 200 – 500 footcandles
High Light: 500-1000 footcandles
Very High Light: at least 1000 footcandles
Keep in mind that light fluctuates throughout the day, from day to day, and from season to season… so it is a good idea to take multiple measurements to get a more accurate picture of the lighting you have available.
Before purchasing a light meter from Amazon, I also tried various light meter apps on my smartphone. To be honest, I didn’t feel that any of them were very accurate, which is why I made the decision to get a piece of equipment specifically designed for the job.
I now feel a lot more confident with the results I’m seeing.
However, there are free apps that you can find by searching for “light meter” that you can try as well!
Resources used for this article: To learn more about lighting and houseplants, click to read my blog post explaining how to assess and understand the natural lighting in your home.
Submit your plant questions below to have them answered in a future post!
To learn more about lighting and houseplants, click to read my blog post explaining how to assess and understand the natural lighting in your home.