How To Use Bonsai Humidity Trays In The Right Way

How to use bonsai humidity trays

One trick that I recently picked up that I wanted to try out, mainly because my bonsai kept drying out indoors was investing in a humidity tray. Humidity trays after all have been used for countless plants as a way of adding moisture in dry environments. So how can you use a humidity tray in conjunction with bonsai trees? 

To use bonsai humidity trays, find a tray that is big enough for the size of your bonsai and its pot. Pour in stones, gravel, or charcoal until the tray has a layer of stones an inch high. Pour in water until the tray is filled and place your bonsai in the middle of the humidity tray. 

So do humidity trays actually work for bonsai? And are there any types of plants where this works best? Keep reading to find out more. 

A lot of you reading this post are just getting started with bonsai. You can find my recommendation for the best bonsai I found here (link takes you to Easternleaf) or the best Faux bonsai here (link takes you to Amazon)

How to use a bonsai humidity tray 

Bonsai humidity trays are a fantastic option to not only keep your plant full of moisture but also avoid any nasty spillages that can ruin your surfaces… especially if you tend to keep your bonsais indoors as much as I do!

To use a bonsai humidity tray there are four steps you need to follow: 

  • Picking the right size tray 
  • Pouring in your material of choice 
  • Pour in water 
  • Place your bonsai

Let’s break these down. 

Picking the right size tray

One of the joys about bonsai is that the trees that we work on all come in different shapes and sizes. 

Whilst most of us are happy with smaller bonsai, some trees can be well over one meter in size!

As such the first step you need to follow when using a bonsai humidity tray is to pick the right size tray. 

If you pick a tray too small your plant won’t get enough moisture or even cause the water to be displayed on the surface around your tray. 

Pick a tray too big and your plant might be getting too much water (yes even for Bonsais) and take up a lot of unnecessary room. 

A good rule of thumb then is to get a tray that has about 3 to 4 times the surface area of your plant pot. 

That being said there are a few important things when it comes to choosing the right tray: 

  • Ensure that you avoid using terracotta clay pots which tend to absorb water and can drain the moisture from your humidity tray 
  • Ensure that the tray you use has a lip at least 1 – 2 inches which will help keep your water and pebbles in one place. 

Now if you’re interested in what I recommend for a humidity tray, check out the Regal Pak (link takes you to Amazon) which is 15 inches wide so should be large enough for most bonsais that need humidifying but also comes in a 3 pack incase you have any accidents.

How to use bonsai humidity trays in the right way - infographic

Pour in your material of choice 

Once you have your tray sorted the next stage is to pick out the material to fill it in. 

For me, pebbles that you can pick up from any garden store usually work best as they are notoriously waterproof however other items such as charcoal or gravel also work well. 

I would avoid mixing the materials so aim to stick to one. 

Once you have picked your material of choice, fill it in your tray right to the top. 

Be careful however not to go over the lip of your tray. 

You might find that your pebbles or gravel are a little uneven so spread your stones until you have a nice flat layer. 

Pour in water

Time to add some moisture to our … err… humidity tray?!

Simple enough, get cold water and pour it directly onto the stones until they have water to cover the stones. 

It is normal for some of the water to be absorbed in between the cracks of your stone so don’t worry if you feel as though you don’t have enough water. 

Place you plant 

Finally, we have to add our bonsai. 

Simply place your bonsai with (its plant pot) in the middle of the moisture tray to start enjoying some of the benefits the tray has to offer. 

Try to keep the plant equally away from all four sides and avoid moving it too much if you can. 

What are bonsai humidity trays? 

Bonsai humidity trays are trays designed to provide moisture to your plant, whilst simultaneously stopping any water leakage from happening caused by watering your plant. Bonsai humidity trays are typically filled with an absorbing stone such as pebbles or charcoal to help evenly distribute moisture. 

Can you avoid watering your plant if you use a bonsai humidity tray?

If you do use a humidity tray it’s important that you still regularly water your plant. This is because bonsai trees of all species need to be watered daily to best acclimatize to their environment and stay healthy. 

Using a humidity tray is a good option to help keep as much moisture near your plant as possible however it is not a real substitute for watering your plant at least once per day. 

Some people suggest using humidity trays and filling them up when you go abroad for a few weeks however I cannot stress enough that this will not work. 

Bonsais regardless of design or breed need water at least once per day in most countries and so leaving your bonsai for that long will just mean it will (sadly) wither up and die. 

What to avoid when using bonsai humidity trays?

If you do decide to use a humidity tray to help keep moisture for your bonsai there are a few things I would consider you avoid: 

  1. Ensure that you use the same material in your tray to ensure even moisture is distributed throughout your plant 
  2. You must continue to water your bonsai regularly and not use the humidity tray as a substitute 
  3. Try not to move your humidity try too much – some breeds of bonsai are incredibly sensitive to the climate around them and so it is important we cause as little damage as possible 
  4. Water the pebbles in your bonsai humidity trays regularly – the best option is to feel the pebbles,s if they feel dry then it is time to water again – typically once every few days works fine for most plant types. 

Should you use bonsai humidity trays?

Bonsai humidity trays are a fantastic option that is not time-consuming to help add moisture and avoid unwanted messes when it comes to watering your bonsai.

That being said the scientific material around the benefits of humidity tray is sketchy at best with some studies showing that the humidity provided by these is being absorbed by the dry air rather than the plant itself. 

That being said I would still recommend bonsai humidity trays for a few reasons. 

Firstly there are some benefits to adding extra moisture to your bonsai tree as most bonsais need more moisture than less. 

Secondly, a humidity tray has more benefits than just adding humidity, mainly absorbing any excess water that your bonsai leaks after being watered. 

There is nothing worse than watering your bonsai ( especially if you keep your indoors) only to realize you didn’t put a tray down and now you have soiled your best furniture ( it happens to us all!)

Finally, because of the pebbles or gravel, these are very appealing to the eye than a lot of traditional plant pots that we keep our bonsai in. 

Bonsai is an aesthetic hobby that prides itself on symmetry and design, so what better way of achieving these goals than investing in a bonsai humidity tray. 

This post was written by Fehed Nicass who has been passionate about bonsai for over 2 years. He currently resides in the Uk and works in sales.

Fehed Nicass

Fehed Nicass has been passionate about all things bonsai and botany focused for the past 3 years. What started out as a hobby has developed as a passion and he is now on a mission to teach and learn.

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