The 'art' of watering bonsai

[Gustavo Martins]

Despite all my efforts, using 4 different types of fungicides, my trident maples are still showing signs fungus: curly leaves with browning tips... But yesterday it came to my mind that maybe it's not fungus, but over-watering. My trident maples are all planted in regular potting soil mixed with LECA in large pots in order to thicken the trunk and I decided to go check. despite the top 1 inch being dry most days, I found that below that, the soil was in fact very wet. So I inserted one wooden stick in each pot and won't water until I see it's becoming dry...

And then I though, what about the other trees? They are all planted in very free draining mixtures (different mixes of scoria, pumice and akadama). But who knows? Although they have no apparent signs of overwatering, I decided to inspect their soils only to find the same result. A very dry top layer (about 1/2 to 1 inch deep) and then very wet soil underneath. The soil drains really well but it is still retaining a lot of moisture underneath the topsoil. Now, everyone says to water when the soil starts to dry. Is this normal and should I water when the top soil is dry, even if underneath is still humid?

I usually water in the morning, but not today. Instead I inserted a tooth pick in all the pots. By the evening, the top was dry, but there was still some humidity underneath in most pots (the day was overcast today). Not sure if I should water or not...

Someone said that it takes 3 years to learn the craft of watering... I'm on my second, so I must learn it now

 

[Tieball]

Good learning. I read, and have heard, that roots don’t take in water as I know it. The roots absorb water vapor. My understanding is that’s why a free-draining is also important to actual watering. Without the tiny air pockets within the substrate there’s no vapor opportunity created...just soggy soil. Well...that’s what I read and interpreted. Someone may correct my interpretation though.

You might attach a photo of the pot, box, or whatever container your using. It could help others understand what you’re learning and dealing with...so they can compare to their own circumstances...it would help me understand more.

Cheers! You’re almost ready to graduate.

 

[just.wing.it]

Potting soil is going to be too wet, for sure...

My free draining inorganic mixes could be watered 6 times a day, and be fine.
With most of mine, I fight getting too dry during the work day.

 

[Gustavo Martins]

Potting soil is going to be too wet, for sure...

My free draining inorganic mixes could be watered 6 times a day, and be fine.
With most of mine, I fight getting too dry during the work day.

But have you checked beyond the superficial layer of soil?

 

[Gustavo Martins]

Good learning. I read, and have heard, that roots don’t take in water as I know it. The roots absorb water vapor. My understanding is that’s why a free-draining is also important to actual watering. Without the tiny air pockets within the substrate there’s no vapor opportunity created...just soggy soil. Well...that’s what I read and interpreted. Someone may correct my interpretation though.

You might attach a photo of the pot, box, or whatever container your using. It could help others understand what you’re learning and dealing with...so they can compare to their own circumstances...it would help me understand more.

Cheers! You’re almost ready to graduate.

All kinds of pots. The tridents are in ordinary large nursery pots. Among the other trees, some are in bonsai pots, some in terracotta pots, others shallow plastic pots. All the same result.

 

[just.wing.it]

But have you checked beyond the superficial layer of soil?

It's usually more ok than I think... especially in the deeper pots...
But my reason is, with a proper substrate, over-watering should not be a problem.

 

[Clicio]

@Gustavo Martins , most probably is the percentage of organic soil in your mix.
I am also very aware that LECA is not so draining as it seems, and keeps a lot of moisture before drying; all my trees with LECA on their mix seem wet all the time, even when others are wilting.
Could be this Leca+organics, maybe you could try a new mix with no Leca and test? Compare?

 

[Stan Kengai]

Despite all my efforts, using 4 different types of fungicides, my trident maples are still showing signs fungus: curly leaves with browning tips... But yesterday it came to my mind that maybe it's not fungus, but over-watering. My trident maples are all planted in regular potting soil mixed with LECA in large pots in order to thicken the trunk and I decided to go check. despite the top 1 inch being dry most days, I found that below that, the soil was in fact very wet. So I inserted one wooden stick in each pot and won't water until I see it's becoming dry...

And then I though, what about the other trees? They are all planted in very free draining mixtures (different mixes of scoria, pumice and akadama). But who knows? Although they have no apparent signs of overwatering, I decided to inspect their soils only to find the same result. A very dry top layer (about 1/2 to 1 inch deep) and then very wet soil underneath. The soil drains really well but it is still retaining a lot of moisture underneath the topsoil. Now, everyone says to water when the soil starts to dry. Is this normal and should I water when the top soil is dry, even if underneath is still humid?

I usually water in the morning, but not today. Instead I inserted a tooth pick in all the pots. By the evening, the top was dry, but there was still some humidity underneath in most pots (the day was overcast today). Not sure if I should water or not...

Someone said that it takes 3 years to learn the craft of watering... I'm on my second, so I must learn it now

Have you considered that it might be an issue with wind dessicating the leaves, rather than a watering or soil issue. I would imagine that your climate is windier than most. Try protecting your plants from the wind, and see if that makes any difference.

 

[Gustavo Martins]

@Gustavo Martins , most probably is the percentage of organic soil in your mix.
I am also very aware that LECA is not so draining as it seems, and keeps a lot of moisture before drying; all my trees with LECA on their mix seem wet all the time, even when others are wilting.
Could be this Leca+organics, maybe you could try a new mix with no Leca and test? Compare?

It's not just the tridents... it's all of them, even the ones with no organics (most actually)

 

[Gustavo Martins]

Have you considered that it might be an issue with wind dessicating the leaves, rather than a watering or soil issue. I would imagine that your climate is windier than most. Try protecting your plants from the wind, and see if that makes any difference.

the leaves? It could be the wind drying the top of the soil too fast yes... but my tree are relatively protected. And the Azores are not that windy.... But yes, that could be the reason.

 

[sorce]

But my reason is, with a proper substrate, over-watering should not be a problem.

This was my initial thought.

There is No art to watering.

The ART is soil choice....

@Gustavo Martins it's a Maple...
I bet you're underwatering.
Maybe something else....(pics?)

But definitely Not overwatering.

superficial layer

This layer becomes the ONLY layer in a Bonsai Pot....so it is anything but superficial.
It is EVERYTHING!

I never let my surfaces dry out much.

By 3-4PM top moss or extra centimeter of DE is Dry....so I splash the tops a bit just to wet the surface.

Consider a taproot in a earth tree....the taproot runs to seek the water table...the constant source of life.
The surface roots are supported by rains and when dry, lay dormant on giant fat established highly forked roots. They essentially sit as a cutting, supported by the tap, until they can grow again in rain.

Resorce.

This is why nursery trees say, "keep well watered until established". What is establishing, is this dual system.

What we are doing in a pot...single system, surface roots only.

Consider a "stick in a pot" WITHOUT these "giant fat established highly forked" surface roots....
They Can't survive in a shallow pot where the surface feeder roots may dry, because they NEED the Juice inside those giant fat established highly forked surface roots to allow for this "sitting as a cutting" without the Taproot.

So in Nursery or training pots....
(Tiles, Ebihara, Radialayer...ahem...)

We don't realize it ....but what we are establishing is these Giant fat juicy highly forked surface roots.....
That are about half the strength of a dual system w/taproot.

The less they dry out, the closer we get to full strength.

Sorce

 

[Clicio]

What we are doing in a pot...single system, surface roots only.

So more watering and care.
Makes sense.

 

[sdavis]

What is LECA?

 

[Anthony]

Gustavo,

this is how we look at it -

soil - inorganic ----- silica based gravel - holds water around itself.
Size - 5 mm

organic - compost - holds 20 times it's weight in water.

So mixes are - 9 inorganic to 1 organic
8 inorganic to 2 organic
7 inorganic to 3 organic

For very thirsty like tamarinds -------- the inorganic can be further
splint into an inorganic that holds water for 3.5 inorganic
3.5 water holding inorganic
3.0 organic

Placement is full sun and we have wind, mild to breezy.

Watering cans are two nozzles ----- one heavy and one like fine rain.

The heavy nozzle - is used as one pass in the morning.
The fine nozzle is used as one pass in the morning
and one pass before 5.00 p.m.
Nothing goes wet of leaf into the night.
Also washes the leaf.

If using leca or home made leca it is 9 parts leca to
1 part organic.
Lecca can really hold water.

This is also why we take a new plant to LUSH for a few
years before training.
Need to know how to Keep it HEALTHY before trying to
train.
Good Day
Anthony

* we also use fired clay properties to help out.
J.B.pines can be grown well in porous pots.
Porous pots can be glazed on the size walls but
not underneath.

Concrete pots also leach away excess water, and like
porous pots cool the soil with the hot sun.

 

[Anthony]

@sdavis ,

https://www.leca.com/