Will a Dehumidifier Kill My Plants

Houseplants bring the natural beauty of a garden indoors, but, different species need different conditions to ensure they thrive. Plants are particular about their needs if they’re going to flourish; they need sunlight, temperature control, and good humidity.

If you rely on a dehumidifier to control the moisture levels in your home, before spending a small fortune at the local garden centre, read our article outlining the ideal plants for your circumstances.

Will a dehumidifier kill my plants isn’t a question with a straightforward answer.

Houseplants tend to prefer humidity levels of around 60%, although certain species thrive on higher or lower humidity levels. Some varieties of indoor plants even help to lower atmospheric moisture levels.

Dehumidifiers reduce water vapour in the air, resulting in the perfect balance where humidity levels are neither too high nor too low.

If plants are exposed to too much dry air, even the most resilient among them will suffer detrimental effects. If your plants are showing signs that they’re about to die, there are rescue methods to help them thrive once more.

The favoured humidity levels of plants

Relative humidity is the measurement of water vapour within a specific amount of air. The results reflect the comfort levels of all living things; humans, animals, and plants.

Plants that are native to the tropics and subtropics tolerate low humidity well.

Of the plants that tolerate high relative humidity, almost all of them naturally absorb moisture from the air.

Humidity LevelSuitable for
80 – 90%Similar to glass and greenhouses. Ideal for tropical houseplants
60 – 80%The optimum humidity for most indoor plants
40 – 60%Equivalent to the humidity level in most homes during summer. Plants require extra care and regular misting
10 – 40%Overuse of dehumidifiers and central heating creates the problem. Only suited to plants that thrive in arid conditions such as cacti and succulents.

Signs that the humidity is too low for houseplants

Several tell-tale signs highlight the fact that the dehumidifier has harnessed too much of the moisture from the air for your plant’s good health.

  • The edges and tips of the leaves turn brown.
  • Buds stop growing, wither and die.
  • Flowers wilt and die far too soon.
  • Stunted growth
  • The lowest or the oldest leaves on the plant fall off.
  • Premature yellowing

What to do

Don’t panic; your plants are still salvageable.

  1. Mist the leaves with a spray bottle; the air has become too dry, the leaves need to increase the moisture level in their tissues.
  2. A discreet vapour humidifier will quickly help to reset the atmospheric balance.
  3. Try moving the plant to a room where the humidity levels are naturally higher. The bathroom or kitchen usually do the trick.
  4. Stand the pots on broken pottery or pebbles to help them retain as much moisture as possible.
  5. Check the temperature; the room may be too cold or hot; the plant might just be crying out for some indirect sunlight.

Plants that survive in low humidity

 They are the type of plants recognised by their waxy or fleshy leaves, designed to help retain moisture.

They are the kind of plants that would fair well in the desert. Cactus and palm plants are prime examples, although begonias, pothos vine, jade plant, and the air plant bromeliad also tolerate low humidity well.

Plants that survive in high humidity

Most plants that flourish in high humidity go one step further; they harvest their required moisture from the air, therefore assisting the dehumidifier most naturally. 

They are mostly robust plants that thrive even if the dehumidifier consistently runs.

The peace lily, Boston fern, and orchids all gain moisture and nutrients from the air. The spider plant grows ferociously, even if neglected and it has little contact with daylight. It draws moisture from the air and removes harmful pollutants.

Is it safe to use the water collected in a dehumidifier to water house plants?

The water from a dehumidifier will have already passed through a filter to make it perfectly safe to use to water plants.

Some suggest that if you have the highest-quality filter that it is also safe to water vegetables and consumables.

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Filters catch airborne particles such as pollen, dust mites, and chemical molecules. The water may contain minute traces of metal from the solder, the most significant of which is lead.

For this reason, we wouldn’t recommend using recycled dehumidifier water on a vegetable patch.

Final thoughts

Plants need moisture from the soil or air to complete the photosynthesis equation. It is when the perfect mix of sunlight, carbon dioxide, and water combine to create sugar and oxygen.

Humidity is a serious player in the circle of life. Too much or too little prevents nature from taking its course.

Artificial environments aren’t strictly conducive to the well-being of house plants. However, even those with high humidity levels that regularly use a dehumidifier, won’t kill their plants – providing they’re the right plants; cared for, watered, and shown some indirect sunlight from time to time.