Temperature and humdity

Temperature and humidity for houseplants

Whether you're just starting to keep and grow plants indoors or you already have an urban jungle, there are a few things you need to know about plant care. Even if you have a watering schedule or the perfect soil, you may not know the best temperature and humidity for houseplants. This is a detail that is often overlooked and that can cause your plants not to grow or not to survive. By keeping the temperature and humidity in your home ideal, you can create an optimal growing environment for your plant. Find out everything you need to know about the optimum temperature and humidity for your plants.

The ideal temperature for houseplants

It will come as no surprise that your plants need the right temperature to grow. Photosynthesis only takes place optimally at the right temperature. Finding the right temperature is therefore very important. But what temperature is needed for what?

There is no perfect temperature for the cultivation/growth of plants. Instead, temperature is a variable value that you can change. Each plant species likes a different temperature. The most important thing is to make sure that the temperature in your space does not fluctuate too much. During the light hours, keep a temperature between 20°C-30°C. During the dark hours, you can lower this temperature to around 16°C. Make sure that the temperature difference between day and night is as small as possible. With temperature differences, you are in fact imitating the seasons. If the difference between day and night is too big or the nights too cold, it will take too long for the plant to recover. There is also a greater chance of mildew developing.

The ideal air humidity for houseplants

One of the biggest problems in keeping plants indoors is spending weeks or months in a room with central heating or another artificial heating method. The good news is that we can prevent or cure humidity problems by knowing the needs of the plants and improving the humidity level of indoor plants.

The measurement of humidity is the so-called relative humidity, where water vapour is measured in relation to the number of water particles that can be found in a certain amount of air. Relative humidity is used to determine a comfortable level that is suitable for animals, people and plants.

So, what is the best humidity level for plants? An ideal humidity level for most adult plants is 60% to 70%. Some tropical plants are used to humidity levels of up to 90%. Many succulents, such as cacti, only need 10% humidity. As a general rule, plants with thicker leaves can tolerate lower humidity.

• 80% - 90%: these are tropical percentages. Plants, especially seedlings, growing in a greenhouse or conservatory can reach over 80%, but indoors this is actually impossible. For some plants, especially young plants or seedlings, this is ideal. For humans, however, it is not.

• 60% - 80%: this is the ideal level for almost all (but especially tropical) indoor plants. However, it is difficult to maintain indoors.

• 60% - 40%: in summer, the air humidity in most homes is around this level, in which most indoor plants thrive. Some plants still need some help, for example by misting.

• 10% - 40%: below 40% it becomes very dry and these are probably the indoor levels when central and artificial heating is used. Cacti and succulents will do well, but most plants will have leaf problems.

To measure humidity in the home, it is advisable to purchase a hygrometer. A hygrometer measures the humidity in a room/area but often also the temperature, which is of course the ideal combination.

Temp 1.webp

The signs of incorrect temperature or humidity

Too low:

  • The edges or tips of the leaves turn brown
  • Leaf edges turn yellow
  • Leaves dry out and shrivel up/ curl up

Too high:

  • Fungus/Mildew on the leaves
  • Fungus/Mildew on the potting soil
  • Leaves and stems start showing signs of rot

Temp 2.webp

Tips for the right temperature and humidity

The right temperature:

  1. Use a (mini)greenhouse: a greenhouse is an option to maintain the temperature around your plant(s).
  2. Beware of draughts: in the winter you have to watch out for draughts, breezes and gusts of wind. To prevent your plants from falling victim to sudden temperature changes, place them away from vents, windows, doors or other places where air can enter from outside.
  3. Beware of overheating: It is normal to want to protect your plants from the cold by turning up the thermostat, but too much heat can be just as big a threat to them.
  4. Group your plants together: If you put your plants together in groups, the air and moisture is trapped between each of them. In this way they also keep each other a little warmer.

The right humidity:

  1. Misting: spraying/spraying the leaves with lukewarm water.
  2. Group your plants: If you put plants together in groups, the air and moisture is trapped between each of them. They can also use each other's moisture from the soil. If you do this, you have to leave some (growing) space between the plants.
  3. Tray with pebbles or hydro grains: The tray consists of small pebbles or hydro grains covered with water. The water should be just below the top of the pebbles so the plant does not suck up water and remains well aerated.
  4. Humidifier: a humidifier is a device that adds humidity to the air through evaporation.
  5. Hang your clothes out to dry: you can also simply hang your clothes out to dry in the house (near your plants) after washing them. This increases the humidity in the air as the water evaporates from the clothes.
  6. Use a (mini)greenhouse: A greenhouse is another option to maintain a higher humidity level for your plants. If you have tropical plants, low humidity can kill your plants.
Hi, I'm Emma, your PLNTS.com guide!

Hi, I’m Emma, your PLNTS.com guide!