The majority of plants that we usually keep indoors reside in tropical or sub-tropical areas. The conditions in those regions are significantly warmer and humid than the rest of the world.
That’s one of the reasons why many plants adapt well to indoor conditions- the inside temperature suits them perfectly and helps them grow well.
My guide on indoor plant temperatures will give the answers to some of the most common questions such as what temperature is too cold for plants, what happens to a plant if the temperature is too low, how cold is too cold for house plants and many more.
Best Temperature for Plant Growth
The vast majority of plants grow perfectly fine in an average indoor temperature, which ranges from 60 – 75°F (between 15 – 24°C). That makes them an excellent choice for various types of homes and offices (with or without many windows).
Of course, some species need more, some less than that, and that’s where you step in, adjusting those degrees (and possibly humidity) to make your plant feel comfortable.
It’s not uncommon during the winter months to turn up the heat, and if your plant resides in a small room where the temp. can built up above 75°F (24°C), then it will find this environment intolerable. The plant will be able to deal with these temperatures outdoors due to humidity and breezes, but indoor environments don’t emulate these conditions.
How humidity & misting can help
If struggle to drop the temperature, usually increasing the humidity around the plant can do the trick. This is achieved by misting the leaves or placing the plant in humidity trays. Of course this will have to be done regularly for as long as the temperature stays above 75°F (24°C).
Plant type varying temperature guide
- Perennials, aka heat-tender species do well in temperatures around 60 °F (or 15 °C)
- Half-hardy / annuals (majority of indoor plants), do well between 50 – 55 °F (10 – 13°C)
- Hardy species can grow in temperatures of 45 °F (7°C)
If you’ve wondered how cold a temperature a plant can tolerate and what point they start to die – it’s below 7°C. No matter how hardy and resistant the plant, it’s too cold for them to live and prosper under these conditions.
Now that you know which temperature range is suitable for plants based on their structure, you will be able to tell what temperature should you bring plants inside. The ideal time is mid-autumn when days become colder (and shorter).
Pro-Tip: Too sensitive or extremely resistant, all plants have one thing in common- they don’t like fluctuations in temperature. So, wherever you keep it, just make sure that the room has a consistent temperature.
Potential Dangers To Consider
Temperature itself can be harmful only if it’s too low or too high, and if the plant is exposed to such undesired conditions for a prolonged period.
Your windowsills are an important determining factor for indoor plant growth depending on the time of the year. We all like to keep our plants on windows, mainly because of the natural source of light and warmth coming from the sun.
However, when we leave windows open, drafts entering your home can significantly drop the desired temperature of the plant.
Any type of draft, especially chilly ones, is not good. Therefore you need to be careful where you will place the container. If you still want to keep it near the window, the best would be to draft proof it.
Also consider winter months. Even with a draft proof window, the area may be too cool for your plant. Rapid shifts in temperatures or prolonged exposure to any of the extremes are not good for your dear green friends. Some slight changes, let’s say between 5 – 10 °F are not harmful or dangerous, but anything more than that is too much for plants… even the sturdiest ones.
Pro-Tip: When temperatures are higher than the recommended level (above 75°F / 24°C) misting can help. By providing more humidity, you will create a balanced environment and your plant will be able to develop properly.
What Are the Most Common Signs That Plant Temperature Is Inadequate?
Just like with other factors, such as watering, humidity and light, your plants will “tell” you if something is going wrong with temperature.
Signs of potential temperature issues
- Flowers die quickly – If this is going on, then it might be too warm inside. Consider relocating plants to someplace where the temperature is cooler.
- Foliage is yellowing and falling – This is also one of the indicators that the temperature is not suitable for the plant. To be more precise, it’s one of the signs plants are too cold.
- Lower foliage drops and wilts, the edges turning crispy and brown – If you’ve spotted this, it’s a signal that it’s too warm.
Pro-Tip: You’ve provided the right temperature for your plant, and it still won’t develop? Then the problem is something other, so consider rearranging your watering schedule, see if it receives enough or too much light, mist it.
I truly hope my house plant guide brought you some valuable insights into how cold is too cold for plants and how to maintain the right conditions for your dear green friends.
Where do you keep your plants during the coldest months of the year? I would love to hear from you, so don’t hesitate to share your experience with me by visiting the contact page and getting in touch!