I took one month out of my life and tortured 19 of the most common house plants with a space heater for 8 hours a night. This is my original data and I have photos so you can see what the heat damage looks like on each of these plants throughout the 4 weeks of the experiment. I won’t lie, I have a heart and a wallet so seeing them suffer or unalive was sad emotionally and for my pocketbook. But, in the hopes this saves more plants than it hurts, I have tortured my plants so you don’t unintentionally torture yours.
Below is a video that explains most of the overall concept of the experiment and its results. If you are considering buying a house plant to place next to a heater I think the video should give you a couple of good suggestions.
If you have a specific plant you own and you don’t know if it will suffer at the hands of a heater then please check out the suggested distances for plants in the table below.
If you would like to see pictures of the individual plant in the experiment, go to the list/table of plants below and click on the one you would like to see.
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Can you put your indoor plant in front of a space heater or heating vent?
As a general rule, plants are safe at 5 to 10ft away from an indoor heater. Placing the plants farther away is advisable if they’re in the direct path of hot air. However, most succulents and some Aroids like Monsteras, and Mini Monsteras actually thrive as close as 3ft from a direct heat source.
Pro tip: I put together a list of very common plants and mixed it in with a few of my favorite houseplants. But, if you don’t see your plant on the list, track down the scientific name and see if your plant is related to any of the plants on the list. A favorite tool of mine is the Google “lens” app, it can often help you identify a plant by pulling up similar images labeled with the name of the plant. If you only find the common name you can then Google “theplantscommonname + scientific name”.
If you own a plant that looks a lot like one that is in my experiment and the plant is in the same genus (the first word in the scientific name of your plant matches one of the ones in the list i.e. Ficus, Dracaena, Calathea, Philodendron), then it is likely close enough of a relative that it will have a similar reaction to being in the direct path of a space heater or any home heat source really. It’s not a guarantee but it’s an OK rule of thumb to determine how heat tolerant your plant may be.
Many Succulents and cacti share heat-resistant traits and processes that really help them survive in these stressful settings. They are a great example of how even just shared characteristics can help you identify other houseplants that would do well in a hot environment even if they aren’t in the same genus.
How Close Can Your Plant Be to a Space Heater/Heating Vent?
Here is my suggested distance from a heater if the plant is being directly blown by the heated air. The estimate for each plant is based on the data from this experiment and is followed by a suggested watering schedule for that distance. If your plant is not in the direct path of the heated air coming out of the vent or space heater then anything 5ft or more away should be fine unless there is no forced air (like a radiator) which could create hotspots that are much warmer than the rest of the room.
If you have a space heater with a fan or have central air then just follow the table below. If you want more info click on the name of the plant for experiment pics and plant-specific advice:
|Plants||Watering||Distance From Heater|
|Snake plant (Dracaena trifasciata)||Bi-Weekly||3ft+|
|Aloe Vera (Aloe barbadensis miller)||Every 3 Weeks||3ft+|
|Monstera (Monstera deliciosa)||Weekly||3ft+|
|Mini Monstera (Rhapidophora tetrasperma)||Every 1-2 Weeks||3ft+ (click name)|
|African Milk Tree (Euphorbia trigona)||Bi-Weekly||3ft+|
|Pin Cushion Cactus (Mammillaria Macosii)||Monthly||3ft+|
|Zebra Cactus (Haworthiopsis attenuata)||Bi-Weekly||5ft+|
|Philodendron “White Wave” (Philodendron “Birkin”)||Weekly||5ft+|
|Calathea (Calathea setosa)||Weekly||5ft+|
|Corn plant (Dracaena fragrans)||Every 1-2 Weeks||5ft+|
|Echeveria “Fabiola” (Echeveria fabiola)||Every 1-2 Weeks||5ft+|
|Jade plant (Crassula ovata)||Bi-Weekly||5ft+|
|Cast Iron plant (Aspidistra elatior)||Every 1-2 Weeks||10ft+|
|String of Hearts (Ceropegia woodii)||Bi-Weekly||10ft+|
|Croton (Codiaeum variegatum)||Every 1-2 Weeks||10ft+|
|Zebra Bromeliad (Vriesea splendens)||Bi-Weekly||10ft+|
|Fiddle Leaf Fig (Ficus lyrata)||Bi-Weekly||10ft+|
|Bird Nest Fern (Asplenium nidus)||Every 1-2 Weeks||10ft+|
|Lucky Bamboo (Dracaena sanderiana)||Weekly||10ft+|
The above list is a quick reference if you are buying plants. If your plant isn’t on the list and you want some of the reasoning behind why I think these plants fit into each of these distance categories, read below:
Thrives 3ft+ Away from Heat Source:
Snake plant (Dracaena trifasciata)
Aloe Vera (Aloe barbadensis miller)
Monstera (Monstera deliciosa)
Mini Monstera (Rhapidophora Tetrasperma)
African Milk Tree (Euphorbia trigona)
Echeveria “Fabiola” (Echeveria fabiola)
Pin Cushion Cactus (Mammillaria Macosii)
I will note that most of these plants have obvious evolutionary adaptations for heat ie: Aloe Vera, African Milk Tree, Snake Plant, Echeveria Fabiola, and Pin Cushion Cactus. As you can see these plants aren’t in the same genus but these 6 are succulent plants and they are well-known for growing in inhospitable environments and thriving on neglect. If you have a succulent you are considering putting close to a heater I would say go for it! Your watering schedule may be a bit faster (like once every 2-3 weeks instead of every 3-4 weeks) but if you are like me you probably won’t be too bothered by that. As long as the plant doesn’t look sickly it is actually ideal for the soil to dry between waterings for most succulents.
Now, both the Echeveria “Fabiola and the Pin Cushion Cactus in fact flowered during the experiment but only for a short time because the heater dried out the flower in about a day or two.
Pro Tip: If you want to enjoy the flowers on the plants you own then take them away from the heater as soon as you see a flower bud. Make sure you aren’t placing the plant in a drastically different light level, the temperature change will be enough of a shock. Try to keep the plant in the same room if possible, just get it out of the direct line of fire of the heater or at least 7 or so feet away if it is still facing the heater.
One last note, I was very surprised to see that the Monstera and Mini Monstera did incredibly well in front of the heater too. Each plant grew new leaves, the Monstera 2 and the Mini Monstera 3+ leaves. If you have a different plant but it is in the Aroid family too, there is a good chance that it may be heat tolerant or may thrive like my 2 plants did.
How do you find out whether your plant likes the heat without killing it?
My suggestion is to put it 5ft away from the heat source and check in with it twice a week for the first month and once a week for the 2nd month, if it looks like you’re doing good after the 2nd month mark or if you start seeing leaf growth that matures in the first 30 days like I did then you’ll know your plants doing well.
Thrives 5ft+ Away from Heat Source:
Philodendron “White Wave” (Philodendron “Birkin”)
Calathea (Calathea setosa)
Corn plant (Dracaena fragrans)
Jade plant (Crassula ovata)
Zebra Cactus (Haworthiopsis attenuata)
This group is a little less simple, the Philodendron “White Wave” is related to the Monstera and Mini Monstera which could explain some of its heat tolerance. This plant just couldn’t grow new foliage at 3ft so I put it at 5ft+ so it can grow like its Monstera cousins.
The Jade Plant and Zebra Cactus are also succulents. Both of these match the characteristics of the plants in the “Survives 3ft+ Away” section. But, these two just didn’t seem to be healthy at 3ft away. There were some shriveled and/or brown parts on both plants so, I put them in the 5ft+ section instead.
The Calathea Setosa was a bit perplexing at first because they prefer to be kept in moist soil and I thought the heater would surely kill it. It actually put up a fight and that is probably due to this variety of Calathea. But it is not invincible and did show damage being this close to a heat source. I was surprised to see that the Calathea “Setosa” I put in the experiment can tolerate almost completely dry soil but its cousin the “Prayer Plant” Calathea (I also own this variety) is why I classify the Calathea as a 5ft+ away plant, this should be a safe distance for most Calathea varieties even if they aren’t quite as resilient as the “setosa”.
And lastly, the Corn Plant, in the Dracaena genus and known for relatively lax watering needs, this plant did ok. Why? Because humidity is important for leaf health in the less waxy leafed Dracaena varieties and even fluoride can cause dead spots on leaves. I wasn’t too surprised to see damaged leaves at only 3ft away for this reason and that is why I recommend 5ft+ away from a heater.
Thrives 10ft+ Away from Heat Source:
Cast Iron plant (Aspidistra elatior)
String of Hearts (Ceropegia woodii)
Croton (Codiaeum variegatum)
Zebra Bromeliad (Vriesea splendens)
Fiddle Leaf Fig (Ficus Lyrata)
Bird Nest Fern (Asplenium nidus)
Lucky Bamboo (Dracaena sanderiana)
For this last group of plants, I placed them in the 10+ feet away list because all of them experienced significant damage and most nearly died. One in fact did die, the Fiddle Leaf Fig. I would highly suggest keeping your expensive fig tree at least 10ft away from a heater for this reason.
Some plants like the Birds Nest Fern and the Croton may actually do well at about 5ft away if you were to amend their soil with some Coco Coir. This helps keep the water from evaporating as fast and keeps moisture available for the roots longer. You’ll notice in the pictures that these two plants are the most expressive about their dehydration and unhappiness. The Croton becomes distinctly droopy and the Birds Nest Fern turns a pale, pastel green instead of its typical vibrant bright green color. Once watered both of these plants sprung right back to life. I think by amending the soil with about 25% Coco Coir it should be able to hold on to the extra water necessary to go a week between waterings for both of these plants. Just don’t go overboard with the Coco Coir and make sure there is mulch, perlite, or some other aerating material so the roots don’t suffocate either.
While the String of Hearts is a succulent, I think the leaves and vines just exposed too much surface area to the hot air and this nearly unalived the plant, I could put this in 5ft away but I have a hunch that you would still experience foliage damage at that distance which is why I opted for 10ft+.
The Zebra Bromeliad was not one I suspected would do well and just like the succulents that flowered this plant’s flower dried up and died too. The heat also dried out the leaves badly and I nearly lost this plant too by the time the 30 days were up. Even a month later I am still nursing it back to health.
The Cast Iron Plant and Lucky Bamboo were a bit of a surprise for me. The 2 plants just couldn’t seem to provide enough water to their leaves to keep up with the rate of water loss and several leaves died. Although, at first, it appeared that both plants were growing, unlike the Monstera and Mini Monstera the growth was quickly destroyed by the heat and even existing adult leaves started to suffer. Both plants showed brown leaf dots or patches and many newer and smaller leaves on the Cast Iron Plant died while the Lucky Bamboo just stopped growing. Both of these plants may be able to survive 5ft+ away but because they stopped growing and started dying I figured 10+ feet away was a safer bet.
- Check Plant Soil Moisture Once Every 3 Days (2 times I did it 4 days apart)
- 8 Hours of Heater Exposure Each Night
- Heater On Swing Mode
- Plants All Thoroughly Watered on The First Day
- No Fertilizers
- No Misting Plants
- Regular Watering Schedule Maintained Until There is Damage Then Adjust Watering
- Experiment Starts 04/01/2022 and Lasts Till 04/30/2022
- Plants Will Stay In Spot for Control For One Week and Observed for Any Changes in Health
- Check For Pests Before Starting
- Damaged Parts of plants will be removed a week prior to prevent any confusion about damage
One caveat about Radiators: I will note that a radiator is different than other heat sources in that it doesn’t force air. It ‘radiates’ heat into a room and if there is no airflow in the room then you will most likely get a more intense hotspot next to a radiator then you would with a forced air system. And a plant, on top of a radiator especially, may fair worse heat-wise than the ones in this experiment because a plant on top of a radiator is surrounded by heat.
1. Heat from contact with the radiator or radiator cover below can cause faster evaporation of the water that’s in the soil or if the soil gets hot enough the radiator may even “cook” the plant’s roots.
2. The heat rising through the air on all sides. This hot air may move slower than fan-forced air but it is nonetheless problematic because of the previously mentioned evaporation. The rising hot air generated by the radiator then pulls the newly airborne moisture up and away from the plant again creating faster evaporation and water loss.
On the same token, less airflow may mean less evaporation, so if there is a radiator cover that doesn’t transfer much heat or if the heat is on but relatively low and the plant is not directly on the heater then I think you will still get similar results to what I get in this experiment. I have found that an increased ambient air temperature is not a problem for plants and instead typically promotes growth as an increased temperature in a greenhouse would as long as the right humidity is maintained too. It is the direct application of extreme heat (100+ Degrees Farenheit) without proper humidity that really seals the fate of a leafy plant’s untimely demise.
I have put together a table and a legend that shows exactly how each plant fared throughout the experiment, I used a moisture meter I bought off Amazon to measure on a scale of 1-10 how moist the soil was. I think this tool is incredibly useful and I would recommend the purchase if you are having trouble with over or underwatering or if you just want to be more accurate with your watering:
XLUX Soil Moisture Sensor/Meter – Over 25,000 ratings at 4.5 stars!
Although the 1-10 moisture scale used in this table is only a relative measurement and not a standard unit of measurement, I think the numbers do illustrate how fast the loss of moisture in the soil can be. Noticing this led me to one of my main takeaways from the experiment: If the soil is able to retain water longer your plant will probably be less affected when exposed to the heat. As long as your plant has adequate soil moisture and aeration for its roots, it may not have any problems at all.There are some exceptions to this rule like the Cast Iron Plant and Lucky Bamboo which had plenty of water but their leaves just couldn’t take the heat. And there are a couple of great examples of this principle like the Croton and Birds Nest Fern which seem to be able to handle being 5ft away in direct line of the heat source as long as their soil remains moist.
Simply adding a little extra Coco Coir to the soil can help it retain moisture and keep the plant safe. You’ll see that plants like the Croton and Birds Nest Fern are water hungry and their soil dried so fast that each was on the brink of death for nearly the entire experiment. And that is because both had very airy and breathable soil mixtures which may not be ideal for a plant in front of a heater. That being said if you do amend the soil to help the plant survive a heater I would recommend getting a moisture meter as I did, just to ensure you don’t overwater the plant either. 25% Coco Coir to 75% potting soil should do the trick for the more leafy plants. Do not add Coco Coir for Succulents, their soil is supposed to get dry between waterings. You can purchase my preferred Coco Coir on Amazon if you follow this link:
Plantonix Coco Coir Brick, OMRI Listed for Organic Use (5 Bricks) – 4800+ ratings – 5 stars!
Pictures/Descriptions of Each Plants Reaction to a Space Heater for 30 Days, 8 Hours a Night:
I took a picture of each plant right before watering Weeks 2 and 3 but 1 day after watering on Week 4 to show the true health of the plant by the end of the experiment.