Smart Gardening

Tips and Tricks for temperature control

Do temperature requirements vary by species or season?

Yes. Here are the three most important phases:

The growth phase (spring)

  • Most houseplants need temperatures above 18 degrees Celsius for their metabolic processes to run optimally and induce growth. Temperature needs will increase after the winter dormancy period.
  • Temperatures below 15 degrees Celsius slow down growth and can cause stress

The flowering phase (spring/summer)

  • Do you want to enjoy your flowers for a long time? Flowering plants love balanced temperatures. Avoid temperature fluctuations.
  • Your plant needs all its energy for flowering  – try to avoid further stress!
  • Keep in mind that some plants only bloom after a dormancy period in a low-temperature environment (see below).

Dormancy phase

Here’s where it gets tricky: Depending on the plant species, the temperature requirements for the dormancy phase differ.

Tropical houseplants still prefer temperatures above 18 degrees Celsius.

  • Avoid potential cold sources such as old windows or drafty front doors.

Subtropical houseplants, especially cacti and succulents, need lower temperatures during dormancy to produce flowers in spring.

  • Place your plant at a sill near a cold window, or any bright location in your place that isn’t heated.
  • The minimum temperature is species-specific: Check our plant library for information on optimal temperature during dormancy.

Reading Plants: How can I tell if my plant is experiencing temperature stress?

Plants are silent creatures. But they do send out silent signals when they’re feeling uncomfortable. Learning to read these can go a long way to establishing a happy relationship.

Signs of cold stress

Look out for one of the following:

  • Brown leaves
  • Yellow leaves
  • Leaves or even the whole plant droops, wilts and looks limp
  • Cacti become discolored or burst open
  • Losing buds can mean that your plants has been exposed to persistent drafts

This is how you turn the leaf:

  • Ensure that the room temperature does not drop below 15 degrees Celsius.
  • Cold damage despite a warm apartment? Then place your plant away from windows, doors, air conditioners, and fans.
  • Drafts are an underestimated yet common cause of cold damage. Give your plant a spot far away from doors or windows.
  • A whole shoot hanging limp and leaves turning brown? Then it’s rest in peace, little shoot. Remove it with a clean knife. Frozen plant parts will not recover.

A few plants that tolerate cold a bit better than others:

  • Epipremnum aureum (ivy).
  • Zamioculcas (lucky feather)
  • Chlorophytum comosum (green lily)
  • Aspidistra (cobbler palm)

Signs of heat stress

Look out for one of the following:

  • Wilted leaves
  • Flowers and fruits fall off quickly
  • Plants dry out very quickly
  • Brown-gray spots on leaves
  • Yellow leaves
  • Several leaves fall off at once – this could also be a sign of large temperature fluctuations

This is how you turn the leaf:

  • Place your plant away from the heat source.
  • Most houseplants prefer indirect sunlight. Place your plant further away from the window.

These plants tolerate heat stress better than others:

  • Tradescantia (three-master flower).
  • Crassula ovata (money tree)
  • Dracaena marginata (Dracaena)
  • Sedum morganianum (Donkey’s Tail)

Good to know: dry air in winter makes houseplants susceptible to bugs. These include spider mites, scale insects, thrips as well as mealybugs. Check your plants regularly for pests.

A quick recap:

  • Temperature affects the plant’s metabolisms and growth processes
  • Depending on the type of plant and the season, the optimal temperature can vary.
  • Wanna be safe?  Most houseplants can cope with temperatures between 16 and 25 degrees Celsius.
  • Last but not least: Avoid direct exposure to heat or cold sources.