Many of our favourite houseplants originate from tropical or subtropical regions of beautiful places like South America, Central America, Australia, Malaysia, and India. Tropical plants live their best lives in relatively humid conditions, but the humidity levels of most homes””especially here in Alberta””are not even close to what one would find on a jungle floor. So, we’re going to break down what humidity is, how to measure the humidity levels in your home and fill you in on the absolute best humidity level for indoor plants.  

So, What is Humidity Anyway?  

Humidity is a measurement of water vapour in the air at any given location. If you have ever heard the term “relative humidity,” it refers to the amount of water in the air related to the max amount of water vapour. It is important to remember that higher temperatures allow for more water vapour in the air, so the chilly temperatures in the winter are not ideal for increased humidity.  

How Do You Measure Humidity in Indoor Plants?  

A hygrometer is one of the best tools available to measure the humidity level in areas of your home where you keep your houseplants. The first version of the hygrometer was invented way back in the 1400s by the one and only Leonardo Da Vinci. Like most tools, there have been many technological advancements and variations.  

Nowadays, you can download apps on your phone that will measure the humidity levels in your home, or you can pick up a digital hygrometer at most garden centers. If you’re looking for a cool science experiment to do with the kids, you can use a pine cone as a hygrometer! Pine cones close up tightly with high humidity levels and open when it’s really dry.  

It is also possible to measure humidity levels in your home using a dehumidifier if you have one already. However, they essentially employ a built-in hygrometer, so we would recommend just purchasing a standalone hygrometer if you are serious about maintaining ideal humidity levels for your houseplants.  

What is the Best Humidity Level for Indoor Plants?  

Humidity levels are rated by a percentage and, while some tropical plants are used to humidity levels as high as 90%, a 50% to 60% humidity level is ideal for most mature houseplants. However, if most of your houseplants hail from more arid regions like the desert (think succulents & cacti), they are happy to chill in a space with a humidity level as low as 10%.  

When grouping your houseplants, keep their humidity preferences in mind! Similar to light preferences, you’ll want to group like with like. A good point to remember is that plants with thick leaves such as Echeveria and Aloe can tolerate much lower humidity levels since they can hold a lot of water in their leaves. So, aim to group your tropical houseplants in an area where you can actively increase the humidity while keeping your cacti and succulents in a drier area of your home.  

Another thing to remember is that all plants require very high humidity levels (90 to 100%) while they are in their growth stage to allow seeds to germinate. Hence why we typically cover seeds with a plastic dome of sorts. It naturally raises the humidity levels, speeding up the germination process.  

Did you know that increasing your houseplant collection is one of the easiest ways to increase humidity levels and improve air quality? See for yourself by checking out the exciting new houseplant varieties available at Salisbury Greenhouse, or learn more ways to increase houseplant humidity in part one of our winter houseplant series.