Most plants grown indoors are native to tropical or sub-tropical countries where conditions are considerably and consistently warmer than what most of our gardens experience. This makes the temperatures within certain rooms in our homes a perfect match for them to grow well.
Most plants: You will find most house plants grow at their best between temperatures of 60 – 75°F (15 – 24°). Some (not many) need less and other’s need slightly more, but plants that grow well within this range are well suited for homes and offices (because many rooms are kept close to these temperatures, already).
Humidity and misting: When temperatures are above the recommended level for that plant – approx 75°F (24°C) you can help improve humidity for your plant by spray misting the leaves. Some plants grow well in higher temperatures which are usually placed in humidity trays and are misted regularly.
Temperature too high: Above 75°F (24°) is too high for most plants indoors , although outdoors they’re fine. The main reason they are intolerant of higher temperatures indoors is because they don’t have the same conditions, such as air humidity and sun light which promotes growth without confining the heat.
Too low: This is much more of a problem than higher temperatures because it damages a plants growth significantly and causes plant death, especially when too much water is also provided.
Rough guide for the lowest temperatures
- Tender plants: 60°F (15°C)
- Half hardy (many indoor plants): 50 – 55°F (10 – 13°C)
- Hardy: 45°F (7°C)
The easiest and most accurate way to identify the correct temperatures for each plant is to look at the specific guidance for each one.
Potential problems to be aware of
Windowsills: While window areas make a great place for plants to sit within summer because of the light and warmth supply – during the winter drafts can cause certain plants problems. You may want to bring your plant back a few inches or so, or draft proof the window.
Quick temperature changes and prolonged periods of cold: The majority of indoor plants can tolerate temperatures above and below what they prefer. However, the real problem that will cause plant growth issues is a sudden drop in temperature or prolonged periods of cold. Between 5 – 10 °F changes are tolerated, but above this your plant could be having problems.
Drafts: The temperature within a room can differ depending on what area of the room it’s measured, and how it is heated. Near doors and windows is an area that has drafts, which can affect some plants if is a bit of a chilly draft. If a plant starts to have problems and it’s near a drafty spot, find it a better spot to reside in.
Signs that temperature is incorrect
- Flower’s die quickly: It’s possible it has been too warm.
- Yellowing leaves and falling: If the leaves turn yellow and fall the likely cause could be dramatic temperature drops.
- Lower leaves falling, leaves wilting, and edges turning brown:Likely cause is too warm.
Note: All of these could also have other cause’s, so do consider each possible problem and eliminate what condition is correct first. If temperatures are right for this plant then look elsewhere (water, light etc.).