Is Watering Indoor Bonsai The Same As Watering Outdoors

Whether you keep your trees indoors or outside, they will need water and I am often asked if this is done in the same way or not.

The reality is that it is pretty much the same, but there will be a few subtle differences which I will go through below, but the basic principles of how and when to water your tree are going to be the exact same, no matter where you are keeping your trees.

The Principles Are The Same

When it comes to watering a tree, it doesn’t matter where the tree is …the same principles apply. The tree will need water and it is your job to make sure that it gets it.

Your bonsai soil should always be damp and your main aim should be to maintain this state constantly.

You will have to check your trees daily and evaluate their needs, regardless of where you are keeping them. Of course how often they need water may change depending on where they are, but the basic principles of watering your tree will always remain the same.

(You can read more about – How To Water A Bonsai)

There Is No Rain Inside

One of the big differences between outside and indoor trees is rain. Rain is huge help if you own outside bonsai as it can basically take care of the watering for you …and if you live somewhere wet like me, this means you don’t really need to water your outside trees too often.

The lack of rain inside means that your tree is going to get 100% of its water from you, and you alone. This means that you do need to put slightly more effort into your indoor trees. You can’t just let nature do the work for you.

The Climate Is Different Inside

While the principles of how and when you water are going to be the same with indoor and outdoor trees, you will find that their climates are slightly different and this is going to affect how often you water.

The temperature, light levels and humidity are all going to be slightly different inside, compare to outside and this can affect how much water the plant wants to drink, as well as how quickly the soil dries out.

This can go in either direction. The climate inside may require you to water more, or it may require you to water less. It really just depends on what is going on in your house, the weather and even the time if the year.

Really you shouldn’t worry too much about this. Just check any trees you own daily and then water accordingly.

You Have To Use Different Tools

When it comes to the actual process of watering, you are going to have to use different tools depending on where your trees are situated.

Outdoor trees are the easiest to water as you can make as much mess as you want. You just need a hose or watering can and you can go around spraying everything.

You cannot really do this inside and you will need to be a little more direct with your watering. I like to use a bottle with a little watering can attachment. This allows me to basically water in the same way, but on a smaller scale and with more control.

I also use an old seed tray as my watering station. I place my tree on this tray, water it and the excess that comes out the bottom is caught, then I can throw this down the drain when I am finished.  

(You can read more about – What Watering Tools Can You Use For Your Bonsai?)

You Will Need A Drip Tray Indoors

You will need to use a drip tray when you are keeping trees inside, which will not be required when you are growing outside.

You could call the seed tray I use for watering a “drip tray” as it certainly does the same function, but I also use drip trays to keep my trees on permanently. This makes sure any excess water that comes from the pots is always caught and isn’t wrecking my house.

(You can read more about – Do You Need A Drip Tray For Your Bonsai?)

You Can Use Slightly Different Techniques

When it comes to watering, I would always suggest you water from above. It is much better for the water to hit the soil and pass through the pot and out of the bottom.

This is going to make sure everything gets wet, but also as the water goes though it will suck air down behind it, helping to oxygenate the pot which is exactly what we want.

This is what you should be doing outside, and preferably inside, but you can actually use a slightly different method, which I guess is called “soaking from below”. Before I had my little bottle top watering can, I used to use this method and if you do it right, it works fine.

I used to place my pot in the sink and fill the sink slowly up with water until it reaches the lip of my pot. At this point water will have flooded the pot through the drainage hole and if you fill the water up to the right level, you will see you the water rise up and be level with your soil.

At this point your pot is totally full of water and now all you need to do is carefully lift the pot out of the water. All the excess water is going to get sucked out the drainage hole and as the water is right up to the soil and you could see it …it is also going to suck a lot of air down into the pot. You can literally feel the sucking as you lift the pot up.

This method can be a little scary as if you fill the water up too much soil can end up floating away as the whole pot is submerged, but if you do things slowly, it is fine. 

This method is also very good for getting used to the feeling of a pot that needs water and a pot that is completely full of water, you will really feel the difference in weight. It does take a little longer to water like this, but if you are in no rush it can be a nice routine to follow. 

Tap Water Is Going To Be More Convenient Indoors

When it comes to watering your indoor bonsai, using tap water is going to be much more convenient. You are probably going to be using one of the two methods I just discussed above and both of these are going to be easier with tap water.

You could still use rain water indoors, but then you have to go outside and carry it in and there is just more risk of spilling it everywhere.

You can do whatever you want, but I would imagine in most cases, watering indoor trees with tap water is going to be the easiest solution.

Conclusion

Hopefully you can see that while there can be some subtle differences between watering inside and outside bonsai trees, the core principles are the same.

The environments may be slightly different and your trees may need more or less water because of this, but you will need to be checking daily.

So long as you are checking often and giving them what they need, that is all that matters. The little details on how you make that happen are not as important as just keeping the tree happy and healthy.

(You can read more about – Frequently Asked Questions About – Watering Bonsai)