5 Must Know Tips For Watering A Bonsai Tree

When I got my first bonsai tree I remember being completely overwhelmed trying to look for information about watering a bonsai tree properly. Now I’ve successfully been watering my trees for years now, I thought I would put together my 5 best tips for watering a bonsai!


Watering a bonsai tree is the more important part of keeping it alive and thriving. It may seem simple but it can be a lot harder than many think, knowing when to water a bonsai, how to water it properly, how to utilize a humidity tray and how to diagnose any issues your tree is having are all extremely important. Keep reading to find out my tips!

Tip 1 – Knowing When To Water Your Bonsai Tree

Knowing when to water a bonsai tree can be tricky but with a few simple tricks and a bit of practice it can be very straightforward with any species. First of all, it needs to be made clear that there isn’t a fixed rule such as ‘water a Ficus every day’. Bonsai trees will all require a vastly different amount of watering depending on the species, age, time of year, climate, sunlight and amount of foliage it has.


So, if all bonsai trees require differing amounts of watering, how do you know when it needs watering? The trick is to check once per day, using your finger. Push your finger about an inch into the top soil to feel for moisture – if it’s slightly moist, this is the perfect time to water your bonsai tree. If the soil an inch down is wet or soggy, it doesn’t need watering just yet!


Key takeaway – Check the soil moisture levels of your bonsai tree daily, all year round by putting your finger an inch into the soil. Water when the soil is feeling moist, not wet.

Tip 2 – Getting The Bonsai Thoroughly Watered

Even if you’re watering a bonsai tree daily, if you’re doing it wrong you could actually be causing as much damage as good! As bonsai are grown in such a confined pot, you can run into a few problems when it comes to actually getting the tree watered properly. These problems include:


  • Root mass being too tight and therefore not able to absorb water/nutrients
  • Only part of the soil being watered
  • Areas of the soil being waterlogged, causing root rot


So, how do you water a bonsai tree properly? For most of my trees I use a very basic, yet effective step by step method to ensure they are well watered every single time.


1. Take either rain water or tap water and start pouring it over the top soil from a low height, making sure you cover all of the soil.
2. Keep doing this until watering is running smoothly out of the drainage holes on the bottom of the pot.
3. Now stop watering and let the bonsai pot sit and drain for 2 minutes.
4. After 2 minutes, repeat this process one more time.


By following this process you can ensure that all of the soil has been well watered and it’s had long enough to start draining properly, as to avoid root rot.

Tip 3 – Quickly Diagnose Under-watering A Bonsai

Under watering is the most common killer of bonsai, especially with newer owners that simply forget to water their new tree. It can be tricky to keep to a watering routine every single day, life does have a habit of getting in the way sometimes but you need to know how to diagnose if your bonsai is under-watered, then know how to fix it fast!


The usual signs of under-watering are the foliage turning crispy and brown in colour, with some falling off as well. If these signs appear it’s important to start taking your watering routine a bit more seriously, watering often and thoroughly. Should you be watering most days and still see these symptoms, there is most likely an issue with water retention in the soil or the roots are really struggling to absorb water, so look at repotting the bonsai tree into new soil and a thorough root prune.


For more information on these symptoms, have a look at my article talking about how to save a bonsai tree with brown leaves.


Tip 4 – Quickly Diagnose Over-watering A Bonsai

Whether it be due to the bonsai pot, the soil or just the amount your water a bonsai tree, over-watering can be fatal and lead to a number of really serious problems for the tree. The main problems over-watering can cause are root rot and mold, from the roots being constantly sat in extremely wet soil. Root rot will eventually kill a bonsai tree unless caught early on, so how can we do that?


The typical signs of over-watering your bonsai are going to be yellow soft leaves and the trunk starting to soften up. If you see these signs, you need to get your bonsai tree out of the pot and assess the situation, most likely pruning away the rotting root mass and repotting it in new soil. For more in-depth information, have a read of my article breaking down whether you have over-watered your bonsai tree.


Sometimes over-watering is caused by a bonsai pot not actually having drainage holes – this is sometimes seen in cheaper trees purchased online. If the pot has less than one or two drainage holes, whenever it is watered it will retain a huge amount of the water, leading to the roots being sat in it constantly and getting infected.


Tip 5 – Actually Using A Humidity Tray

Humidity trays are extremely useful for keeping indoor bonsai trees healthy as they provide that extra moisture to the roots. A lot of people just think that it’s a drip tray to catch extra water after watering the tree but it’s much more than that!


For an indoor grown bonsai tree, ensure you always have your humidity tray filled up with rain or tap water. If you have roots dangling out of the drainage holes they will need to be trimmed or the bonsai repotted as they will sit in the humidity tray water and get infected after a while.


Related Articles –

4 Important Things To Look Out For When Growing A Bonsai // Misting A Bonsai Tree

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