Watering after first repot

What’s up mirai community!? I’ve been a lurker for almost a year as I’ve been getting my bearings and digesting as much bonsai as I can but it’s time for my first post. I’ve only been serious about learning bonsai for about a year so bear with me lol.

I’m curious what everyone’s experiences, techniques and thoughts are about watering a nursery stock tree that’s just had it’s first repotting. Particularly coniferous with a pretty significant amount of nursery soil left intact in the root system. If it’s planted in well draining inorganic soil, I’m assuming I should continue to water to the level of moisture in the leftover nursery soil. As the temperatures begin to rise and the trees wake up, will the drier inorganic soil hamper the root systems growth at all? Or should the moisture of the nursery would keep the Immediate surrounding inorganic soil moist enough? Just been thinking about it so figured I’d ask. For some background I live in Florida and our spring is right around the corner. They’re all junipers, and they were all styled last year. Thanks in advance for the info!


Have you watched the livestream on spring watering? https://live.bonsaimirai.com/library/video/spring-watering
The goal is to give the plant what it needs. Balance of water and oxygen.
Too much water is bad… too little water is bad.
Each tree has individual needs. I have learned to not water on a schedule, a major cause of my dead tree collection!
Root rot and tip blight can both be the results of over watering.
So ….
after repotting the care changes. Never bare root a conifer, so they will always have some of the field or nursery soil as well as bonsai soil mix.
The nursery stock repot stream addresses the transition.
Observe the tree and container : examples include a chopstick in the pot to see moisture level, by comparing the weight of the tree and container when watered and when dry, using a moisture meter, observing the health and condition of the tree.
So learning to water properly is a learned skill.
I hope you persist and learn from the many sources available today.
learn lots, share with others, have fun


Thanks bob! I’ll re-watch that nursery stock video. My bonsai iceberg has only fit so many penguins on it so far from all of the videos lol. Luckily I knew not to bare-root my junipers and I don’t water on a schedule so I guess I learned something at least… lol

OMG! here, in Belgium, it is rainy, wet, cold …The good thing, is that we have to worry less in term of watering … on the other hand, we have to take that wet weather into account in our soil composition.
Welcome with your first post @Jdaws

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I think that as @Bonsai_bob said, each tree has its own needs and in a way I think we must teach ourselves to follow our instinct about each tree by observing them closely every day, I’m still struggling with it myself but yeah, feel that soil, touch it, make sure its not too wet or too dry and you’ll strike that perfect balance, specially if you employed proper repotting procedures and used the right kind of soil for the particular horticultural needs of each plant.


i believe also a kind of beginners mistake is to go out and water the trees as understood in a single task ( i go water the bonsai, taking the hose over all of them - which is many times seen in general Bonsai videos) vs. go out and water the individual tree according to the needs of that tree (so go out in the morning to provide water to those trees in need at that time, go out again for different ones at different times…


Hey @Jdaws,

Don’t be a lurker, your question is awesome. Keep them coming. If you were to water it to the level that the inorganic soil is at the proper moisture level then the organic free flowing soil will be too moist most of the time. Alternatively, if you were to let the organics dry sufficiency, your inorganic would be too dry. Now, you need the roots that are in the organic soil because they are potentially the only ones you have after the repot, you also want to encourage root growth in the inorganic soil so that in the future you can come back and have enough roots there to allow you to replace the organic soil. Also water will diffuse by osmosis from the wetter organic to the drier inorganic to some extent. So it is a bit of a balance and hard to have a rule but I would not let the inorganic become bone dry to the level that I would not let it get to if it were part of a system with only inorganic in it. Watering is the toughest thing in bonsai and this mixed organic/inorganic soil situation is the most difficult to manage while being the most common to encounter as we start doing bonsai.


with your permission, I will ask Ryan this question at today’s live Q&A.

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Thanks everyone for the responses! @rafi you hit the nail on the head. Yea, feel free to ask Ryan today! Looking forward to it.

I’m curious if being sure to top dress (only the new inorganic soil) helps to balance this issue a bit. :man_shrugging:t2:

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Fresh from the live Q&A oven: If you did the repot properly, in the sense that the interface between organic and inorganic particles is rough and you didn’t manicure the roots during the removal of the part of organic soil. Then, you will have a meshing in of the organic and inorganic with root already at least partially occupying the inorganic soil. If that is the case, then using the state of the top dressing as the sensor for water then, you do as you would no matter what the nature of the substrate is. If the top dressing is dry, then you need to water. If it is wet, you don’t. If on the other hand, you manicured the roots and you decreased the flat-edged surface of the organic soil in the nursery container, to a flat-edged surface off organic soil just smaller to fit the bonsai container, then you will have a harder time to balance the water content of the two types of substrate or trust the state of the top dressing fully as a measure for watering. And of course how often you’ll actually need to water will depends on how much foliage the tree has, the species, etc.