Brown spotting on trident & Japanese maples

[NeedlesAndLeaves]

We all share knowledge on experience, which is a good thing.

We had a few hot early summer days here in the Netherlands. 27 degrees, not that special for mediterranean countrys, but going to extremes for us.
Already giving burnmarks on my maples.
Not even summer yet.

Less or damaged leaves means less energy production.
I have had maples with all their leaves damaged because of “dutch sun”.
I was lucky enough they did flush the next season.

But: growth and thickening stops. And it feels like a year wasted.

My maples do better in partial shade.
But I agree trees can adjust (to a certain point) to their environment.

 

[NeedlesAndLeaves]

Have a look at the threads of SeanS

 

[zita]

We all share knowledge on experience, which is a good thing.

yes, i ve learned a lot here myself from others, so thx at all and kudos to bonsainuts.

We had a few hot early summer days here in the Netherlands. 27 degrees, not that special for mediterranean countrys, but going to extremes for us.
Already giving burnmarks on my maples.
Not even summer yet.

yes, not even summer yet and reports here are coming from UK and NL, not know as overly sunny

Less or damaged leaves means less energy production.

no and yes.

A leave that is exposed and perfoms in the sun is multiple times more worth than one that is hidden. Every leave on your tree has its very own number in terms of Photosynthese and hormonproduction.
The unexposed ones are negative as a whole as they produce not significant percentage and at the same time they interrupt the light shining on other leaves. Less can be much more.
"damaged" is no good, yes, but sunstressed isnt damaged imho.....leaves that are unexposed and got weak and turning funny, these are damaged or potentially will be.

I have had maples with all their leaves damaged because of “dutch sun”.

it wasnt the dutch sun, rather not enough sun prior during fall. Got weak and shows it on first stress.
I do not like to prune in spring.....but when the tree grows strongly and leaves start to cover the light of lower branches, they have to be removed.
you want continious light everywhere from start of the season. this is key!!

I was lucky enough they did flush the next season.

lucky but that is what it is, the tree was progressing. As long as there is a slight hint of green left on the leave, it means the tree is protecting and reacting.

But: growth and thickening stops. And it feels like a year wasted.

and looks like shit.
but.....if you really want to thicken the trunk, you want branches low dowm and you want them to perform.
You will have to let the light through to them....means cutting off upper branches....

My maples do better in partial shade.

for a short period yes, longterm certainly not. Please put one of your trees in full sun no mather what and prune it only with sun in mind (no leave is shadowed from another). (when pruning, cut the entire branch or at lest entire side branches)
I promise you, it will be your best performing tree withhin two seasons.

But I agree trees can adjust (to a certain point) to their environment.

continious light is what they adjust to the very best.

 

[RoadManDenDron]

Please put one of your trees in full sun no mather what and prune it only with sun in mind (no leave is shadowed from another)

I need to see your trees first, if i like how they look, I'll follow what you say,

I don't wish to argue,

Just know what you're saying goes against the teachings I've previously had and need to see some demonstration rather than just words on the Internet before I risk my trees

I'm turn i can provide you with embarrassing pics of sun scorched maples that were not even receiving full sun whose leaves are clearly not functioning optimally, never mind strengthening the tree

 

[zita]

all right, which cultivar would you like to see? Then again, got to figure out how to uploud photos.
And it will be no challenge as it is not even summer yet. August is the Master where i am.

we just had a few days around 35degrees and all the trees are fine...not a single leave browned.

some exceptions:
-a maple just purchased and not used to full sun yet
-a maple that grows as a dwarf....outside perfect, but inside little light and leaves look sick
-a maple that fell out of its pot during storm and the roots got damaged.....looks as sundamaged but isnt.

and yes, do not do anything not sure about. Very especially not with the trees you like.
You could experiment with one tree only first. Buy a cheap one for example to play.

yes, would like to see your trees. Dont feel embaressed however it looks. The hobby is more about the way and progessing rather than results.

 

[RoadManDenDron]

I don't want to say cultivar is not important,

Because I believe cultivar is very important, for example I notice my gold/yellow leaf varieties really seem to not like the sun

I don't know what cultivars you have,

I would like to see pics of how far you let the damage go, the trees that can withstand the sun and their leaves and the pots you are keeping them in

Information about the soil they are in would also be useful, as well as how you feed or supplement

I have many maples, actually, I have too many maples.

I shade what I can as best I can. I have trees in the ground, nursery pots, training pots and bonsai pots of many cultivars

This year I have 2 that couldn't handle the sun in their position,

1 as I mentioned was as good as dead last year and I can't believe it woke up in spring, it was in a very exposed position to wind and sun

It still started to burn this year but I finished my shade house and it has resprouted weak but new growth in there, it is a yellow leaf variety


The south of the UK is sunnier than the north where I am, my friend down there keeps his maples in full sun but he has them in gravel trays like I use for my small trees

Uploading is simple, under the type box is a box that says attach files and a paperclip

You can either just add them and they will appear under your reply as little thumbnails,

Or you can actually insert them Into your message from there

Looking forward to seeing them!

 

[MMJNICE]

Hi all! I recently found some brown spotting on my trident and Japanese maples. We did have unexpectedly hot days last week, so I’m unsure if these spots are sun burn/leaf scorch or a fungal issue. Wondering if anyone has had experience and could tell me what they think it might be.

Thank you!

Get some mancozeb fast!!! That black spot will completely destroy your growth for the year. Cut off all the leaves that have major spots and burn them..

 

[MMJNICE]

I know exactly what that is... mancozeb fast!

 

[NeedlesAndLeaves]

I know exactly what that is... mancozeb fast!

I don’t know where @Ghoulbath is located but Mancozeb is prohibited in the Europian Union.. there is a lot more available in the US.

All the stuff Bjornholm advices can’t be bought here unfortunately!

 

[zita]

I don't want to say cultivar is not important,

Because I believe cultivar is very important, for example I notice my gold/yellow leaf varieties really seem to not like the su

I don't know what cultivars you have,

I would like to see pics of how far you let the damage go, the trees that can withstand the sun and their leaves

ah yes, forgot, i did get a tall orange dream from a friend this winter and it was said to not give more than 2 hours of sun per day.
I placed it at the sunniest place i have, means that apart from full sun it gets reflections from the bright wall from the house too and also from thre bright stone floor.
That tree doesnt look good by now, i mean the leaves look somehow sick and some browning, crisping and spotting. Not to bad yet and yes, it wont be moved to shade no matter what.

and the pots you are keeping them in

Information about the soil they are in would also be useful, as well as how you feed or supplement

all kind of different pots. I have trees coming in and getting out.
The incoming ones are what they are.....when i do repot:

zeolith
pumice
lava
coco choir
kork granulat (very good while worthless)

haurin acid
hyrio Gold

I have many maples, actually, I have too many maples.

I shade what I can as best I can. I have trees in the ground, nursery pots, training pots and bonsai pots of many cultivars

This year I have 2 that couldn't handle the sun in their position,

1 as I mentioned was as good as dead last year and I can't believe it woke up in spring, it was in a very exposed position to wind and sun

It still started to burn this year but I finished my shade house and it has resprouted weak but new growth in there, it is a yellow leaf variety


The south of the UK is sunnier than the north where I am, my friend down there keeps his maples in full sun but he has them in gravel trays like I use for my small trees

Uploading is simple, under the type box is a box that says attach files and a paperclip

You can either just add them and they will appear under your reply as little thumbnails,

Or you can actually insert them Into your message from there

Looking forward to seeing them!

 

[zita]

ok thx on the advise how to uploud.....very easy

i made more photos, but i have to learn to make better ones.

1st and 2nd photo is the orange dream.....on its way to get burned. i do not care at all as long as the lower part will survive. The tree was bigger when i got it...it the fell down in the wind so i chopped some. Orange dream does not like to be cut in spring, but there was no choice.
photo3 is a dejosho, not meant to look good. the branches are arranged for max sunlight. very especially on the lower part as the only purpose is to thiken the trunk. later the tree will be cut at half the hight and all branches removed. in a year or two.
photo4 is a little yammamoji, was a green plant and now in sun for 2 weeks. turned dark and leaves wont survive. at the same time, already new buds coming out so they will overtake then.
photo5 some more cultivars.

 

[zita]

Get some mancozeb fast!!! That black spot will completely destroy your growth for the year. Cut off all the leaves that have major spots and burn them..

as for me that tree has no problem at all. it was a wet spring in europe and that is what they do look like then. It will develope new leaves and then you can cut the ugly ones off.
why would you spray heavy poison on it?

 

[zita]

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humin acids.......not haurin as i wrote

 

[RoadManDenDron]

Nice shishi, is the one on the end the air layer from the big one?

my new growth after die back is weak small leaves I do not expect to be anything other than weak tiny leaves.

At least it will keep the sap flowing and hopefully next year I'll improve by not allowing the burn in the first place

 

[RoadManDenDron]

Heres mine that got burned



You can hopefully see it has less than half the ability to photosynthesise than it would have had it not burned

Here are some healthy leaves on my trees that recieve morning sun or dappled shades, protection from wind and the extremes of the sun



These are operating to their full potential, undamaged and providing enough energy for the trees to send healthy extensions

 

[zita]

Nice shishi, is the one on the end the air layer from the big one?

no, big one is a mikawa yatsabusa. both in nursery pots/soil still. both were big bushes and are just in the prosess of getting chopped down step by step. the shishi will be built up new from the nebari. The Mikawa gets a new set of branches.
the photo was choosen because every tree there is another AP cultivar in full sun.

my new growth after die back is weak small leaves I do not expect to be anything other than weak tiny leaves.

hey good evening and thx for the interesting photos.
i do have a completely different view on it.

first, i do like the trunk. chopping the right branches down the road will give it a great line.

then, thouse weak tiny leaves are bad ass. MONSTERS !!!
they do numbers of photosynthyse you wouldnt belive.
And, they become bigger....and lucky man, just very short after the 1st leaves there are already more visible...2nd and 3rd with finally short internodes on that tree.

thouse new leaves are just overtaking the lead.
the tree is safe. the difference now is that thouse new ones wont burn almost anymore.

 

[Paradox]

@zita and @Ghoulbath
Please put your location in the spot provided for it on your profile so people will see it on your posts and don't have to repeatedly ask you where you are.

Location is very important for bonsai advice

As for the topic, my maples get morning sun and afternoon shade. Been keeping them this way for 14 years after having some get crispy leaves in August.

Leaves are new each, the same leaf does not regrow year after year so i don't buy that you can sunproof leaves for 2 years and then they will magically be fine. I've never seen any expert on maples advocate for letting the leaves burn for 2 years. It's counter intuitive.

My maples grow well for me and I haven't had sunburned leaves in years. I'll keep doing what works for me