Poinsettias are one of my favorite seasonal plants, with their elegant red leaves evoking the feeling of Christmas time in my heart!
And I share your frustration with their leaves dropping as soon as you buy them and bring them home! This has, of course, happened to me and many other houseplant enthusiasts due to their notoriously fussy care requirements.
In this article, I share with you everything that I have learned about how to pinpoint the problem and how to care for poinsettias in a way that reduces the risk of the leaves falling off, with tips and tricks to keep your plant healthy.
The most common reason I see for poinsettias dropping their leaves is due to sudden exposure to temperatures cooler than 55°F.
Poinsettias are native to hot and dry forests in Mexico and do not tolerate cold temperatures. Even brief exposure to temperatures cooler than 55°F can cause all of the poinsettia’s leaves to drop.
This is why your poinsettia can die from something as innocuous as taking your poinsettia from the store to your car at a cold time of year (I know, this is really annoying!).
However, it should be noted that poinsettias drop their leaves due to stress if the conditions in which they are cultivated are contrary to the preferred conditions of their natural habitat, so to prevent poinsettia from dropping their leaves, it is important to replicate some of the elements of their natural environment.
I think it is worth me highlighting that the poinsettia’s red leaves, which are displayed at Christmas time, are actually bracts (which is a specialized red-colored leaf, rather than a flower) that fall off as part of a natural cycle after Christmas.
Here is a table summarizing the most common reasons I encounter for poinsettias losing their leaves:
Common Reasons for Poinsettia’s Losing Their Leaves: | Explanation for Leaf Drop: |
---|---|
Cold Temperatures: | Temperatures cooler than 55°F (13°C) cause the leaves to drop, even if the exposure was brief. |
Temperature Fluctuations: | Poinsettias prefer a stable temperature range of 65°F to 70°F (18°C to 21°C) during the day and around 60°F and 65°F (15°C to 18°C). Any significant, sudden fluctuation in temperature (whether hot or cold) can cause leaves to drop. This is often due to indoor heating in the Winter. |
Excessive Air Flow/Low Humidity: | Poinsettia leaves should be misted as they prefer high humidity. Air conditioning, indoor heating, and draughts can all reduce humidity, causing the leaves to lose moisture and drop off. |
Overwatering (leaves wilting, then falling off): | Watering the poinsettia too often deprives the roots of oxygen and interferes with the root’s ability to draw up moisture, causing the leaves to wilt and drop off. |
Too Much Shade: | Poinsettias require bright, indirect light and can drop their leaves if they are in too much shade. |
The Red Leaves (bracts) Naturally Drop After Christmas: | The red leaves that are associated with Christmas time often fall off after Christmas, as they are displayed to attract pollinators in Winter in their native environment and drop off due to the natural cycle of the poinsettia. |
Keep reading for all my tips and tricks to keep your’s looking healthy…
Temperatures Cooler than 55°F (13°C) Causes leaves to Drop
I discovered, the most common reason for leaves dropping prematurely is because it has been exposed to temperatures lower than 55°F (13°C). Poinsettias are native to hot and dry environments in Mexico and do not tolerate even brief exposure to the cold without dropping their leaves.
If the poinsettia has gone from a beautifully presented store-bought plant with abundant red leaves (bracts) and started dropping its leaves shortly after purchase, then it is most likely that the poinsettia has been exposed to unfavorably cold temperatures whilst in transit from the store to your house. I know this can sometimes only be a minute or two, but that is how fussy poinsettiasF are!
Poinsettias are, of course, most often bought in the Winter in the run-up to Christmas when temperatures lower than 50 degrees F.
It could have also been stored badly at the garden center or store where you bout the poinsettia if the shop has temporarily stored it outside or in a cool area with an open door.
Once the poinsettia has suffered the cold shock, then I’m afraid there is not much you can do to revive it, other than follow the best practices of cultivation by misting any remaining leaves every day (poinsettias prefer some humidity), water the potting soil thoroughly once the surface of the soil has begun to dry and locate the poinsettia in an area of bright indirect light with stable room temperatures.
However, I must emphasize if the poinsettia has lost its red leaves before Christmas, it cannot regrow new leaves until the following year.
Temperature Fluctuations Result in Falling Leaves
Poinsettias prefer stable daytime temperatures of between 65°F to 70°F (18°C to 21°C) and a slightly cooler nighttime temperature of between 60°F and 65°F (15°C to 18°C) to maintain their leaves.
Poinsettias have adapted to growing in environments with these specific temperature ranges and they do not tolerate any significant deviation of either hotter or cooler temperatures, or they lose their leaves due to stress.
This was a problem for me during Winter when I lived in my apartment in New York. My indoor heating raised the temperature too high at night, contrary to the poinsettia’s preferred conditions of slightly cooler temperatures at night, and many of the leaves dropped off my plant!
To try to maintain any remaining leaves, I recommend locating the poinsettia away from any direct heat sources, such as forced air or radiators, and away from cool, draughty window sills.
My best tip: I personally placed my poinsettia in my bathroom. The natural humidity of the bathroom was more favorable, and my poinsettia kept its remaining leaves.
If the poinsettia is placed on a window sill and the curtains are drawn, then this can create a micro-climate that is too cold for the poinsettia to tolerate, and the glass of the window pane can be significantly colder than the rest of the room.
A common mistake I see is when the poinsettia’s leaves are in contact with the window, as they can suffer cold damage and drop off.
An area in a living room with bright indirect light, away from draughts and away from any direct sources of heat, or a humid bathroom creates the optimal environment for the poinsettia to retain any remaining leaves.
Excessive Air Flow and Low Humidity
Poinsettia have adapted to grow in a relatively stable environment and actually prefer relatively high humidity.
If the humidity is too low this can sap too much moisture from the poinsettias leaves and cause them to drop off as a way of conserving moisture.
The indoor air is often significantly dryer in winter than any other time of year due to the increased use of indoor heating, which dries out the air. Also, consider the use of forced air, air conditioning, or open windows and doors, which can all cause temperature, airflow, and humidity to fluctuate unfavorably for the poinsettia.
Useful tip: You can counteract the dry air by misting as I used to, but from experimenting, I found the most effective way of increasing humidity is with a specialized plant humidifier, which is available online, which emulates the humid conditions of the poinsettia’s native environment.
Poinsettia Leaves Wilting and Falling Off- Overwatering
I spoke to an expert grower of poinsettias about this, and they told me the most common reason for poinsettia leaves wilting and then falling off is because of overwatering. Poinsettia prefers the soil to dry slightly between bouts of watering. If the soil is consistently damp from watering too often, the leaves begin to wilt as a sign of stress before dropping off due to too much water, causing a lack of oxygen in the soil.
Poinsettias are native to Mexico, where they grow in relatively dry forests with relatively high humidity.
The frequency of rainfall and the drainage characteristics of the poinsettia’s soil in their native environment means that the poinsettia has adapted to slightly dry conditions and prefers the surface of the potting soil to dry before watering again.
If the soil is watered too often, then the excess water in the soil excludes oxygen from around the roots. This prevents root respiration, interfering with the root’s ability to draw up moisture and nutrients from the soil.
If the poinsettia’s roots cannot draw up moisture and nutrients, then the moisture does not reach the poinsettia’s leaves, which causes them to wilt. If the poinsettia is consistently overwatered for an extended period then the wilting leaves eventually fall off.
How to Save it…
Whether or not your poinsettia can be saved depends on how long it has been in damp soil, as it can develop root rot, and the poinsettia can die back if the soil is saturated for too long.
However, I find sometimes the poinsettia can be saved if you scale back the watering to mimic the moisture conditions of the poinsettia’s natural habitat.
This means waiting for the surface of the soil to feel dry to the touch before watering the poinsettia again.
How long it takes for the soil to dry at the surface (and therefore how often you should water your poinsettia) varies according to different conditions (such as the temperature of the room, the size of the pot, etc.) I must warn, there is no universal advice for how often you should water your specific poinsettia as it is subject to your specific conditions in your house.
However, I wait for the surface of the soil to feel dry before I water, as this should achieve the balance of providing the poinsettia with enough moisture to meet its requirements whilst avoiding leaf drop due to overwatering.
In my experience, this typically this means I need to water my poinsettias around once a week with a generous soak.
Ensure that water trickles from the drainage holes in the base after watering to ensure that the potting soil is evenly moist so that the roots can access the moisture they require.
If you scale back the watering to replicate the typical soil moisture conditions of the poinsettia native environment, then it can potentially recover.
(Read my article, how to revive a dying poinsettia).
Too Much Shade can Cause Leaves to Fall Off
Poinsettias thrive in bright areas with lots of natural light. If they are located in a shady room, perhaps with a north-facing window without much bright light, then the poinsettia can start to lose its leaves.
Poinsettias are native to hot and dry forests in Mexico and grow under the canopy so that their leaves are protected from harsh direct sunlight, however, the light under the canopy is bright which charges the poinsettia with energy for displaying the red leaves (bracts) and flowering.
If the poinsettia is in too much shade, it does not have the resources it requires to grow and display its red leaves and flowers, which can result in the leaves dropping off.
So to avoid this happening, my trick is to mimic the conditions of the poinsettia’s native environment by placing my poinsettia in a nice bright spot in the house with bright light, yet avoiding any direct sunlight, to achieve the optimal balance of light for the poinsettia to retain its leaves and grow.
Usually, I place my Christmas poinsettias on the brightest window sill with a sheer curtain that diffuses the light to create optimal conditions, or I place them in my bathroom, which has frosted glass that has the same effect as a sheer curtain that diffuses the light so that my poinsettia thrives.
The Red Leaves (Bracts) Naturally Drop After Christmas
The red flowers, as I discussed, are not actually flowers but specialized leaves called bracts, which are colored red in order to attract pollinators, whereas the flowers are in the center of the bracts and are actually rather small white flowers.
These leaves (bracts) naturally fall off after they have fulfilled their job (to attract pollinators to the flowers) in their native environment and do not regrow until the following year.
Poinsettias require a specific sequence of events around Christmas time in order to produce the red leaves and flowers.
Poinsettia rely on being photoperiodic which means the light conditions indicate to the poinsettia to start to produce the red leaves in time for their key pollinator to find their flowers.
When there are fewer hours of daylight compared to hours of darkness for a period of 5 weeks or more, this stimulates the poinsettia starts to display red leaves and the flowers emerge.
If there is any unnatural light during the 5 week period that interrupts the period of darkness overnight from turning on a light, then this can prevent the poinsettia from developing new red leaves.
This can be a tricky business. I place a cardboard box over my poinsettia to exclude the light at night (from artificial indoor lights).
To learn more about how to get your poinsettia to flower again and display its red leaves, I recommend you read this university article, which explains the sequence of events required to stimulate flowering.
Key Takeaways:
- Poinsettia drop their leaves due to overwatering, low humidity or they are exposed to temperatures cooler than 55°F (13°C). Poinsettias naturally drop their red leaves after Christmas as part of their seasonal cycle.
- Poinsettia leaves wilt and drops off because of overwatering. Poinsettias are native to hot and dry climates and prefer the surface of the soil to dry out between each watering. If the soil is too damp, then the poinsettia leaves wilt and drop off.
- To save a poinsettia that is losing leaves, recreate the conditions of the poinsettia’s native environment by increasing the humidity with regular misting, maintaining a stable temperature range of between 65°F to 70°F and wait until the surface of the soil dries out before watering.