Sun scorch or something else..?

[Haydz]

I recently picked up this maple from a pop up shop here in SoCal, I couldn’t say no. Now the plant is usally on my balcony and I have a sun blind to help with some stippled shade for my other maple but up until last week we have been very overcast and cloudy so I’ve had it closest to the open to get as much of that cloudy sun as possible, now where I believe i fucked up was we got an unexpected mini heat wave with blue sky’s, 85-95 F days, and a UV index of 10+ and this little guy was right there to take it all in, since then I have moved him back away and closed my sun curtain to break up some of that immediate sun for a “dappled shade” if you will… now where I am second guessing myself is this maple came in a soil I usually don’t work with, now I’m pretty good at gauging when water is needed and the whole top of the soil came covered in these river stones which seems to keep the moisture in pretty well but now I’m worried that im missing diagnosing sun scorch for over watered or a root problem… I usually only water when the top quarter to half inch is starting to get wet dry, (like it looks darker but when you pinch it in your fingers it kinda crumbles away without anything sticking to your fingers)

So now I take to the bonsai forums lol… what do yall think and what would yall do any and all recommendations are welcome

 

[nuttiest]

What side is the porch? If it gets direct sun the heat of the black stones is not good.
If you need a soil decoration find some Santorini stones, they reflect a lot of heat.

 

[Deep Sea Diver]

Dunno, doesn’t look like sun burn to me.

Possibly a water quality issue. @Bonsai Nut used to live down there, perhaps he can help?

Best
DSD sends

 

[Bonsai Nut]

It is very tough to keep Japanese maple in Southern California. The big culprits are:
(1) Bad water. Unless you have a water softener, your water out of the tap is likely very alkaline and high in sodium. My water out of the tap was 8.5 pH, when Japanese maples prefer water that is slightly acidic (like 6.0 pH). Using acid fertilizer will help, but not completely resolve this issue.
(2) Intense sun. You can solve for this with some version of shade cloth or sun covering.
(3) Low humidity. Combined with the sun, if you leave your tree outside on the wrong day, the leaves will crisp. If the Santa Anas are blowing you have to give it wind and sun protection - almost like a shadecloth tent - or the tree will burn up.

I tried many times to keep Japanese maples in Southern California, but was almost completely frustrated. I was able to keep a single Sango Kaku alive in a sheltered corner of my yard under shade cloth, but the tree never looked that great, and sadly, in the Fall the tree's leaves would dry up and fall off the tree without any autumn color.

 

[Haydz]

It is very tough to keep Japanese maple in Southern California. The big culprits are:
(1) Bad water. Unless you have a water softener, your water out of the tap is likely very alkaline and high in sodium. My water out of the tap was 8.5 pH, when Japanese maples prefer water that is slightly acidic (like 6.0 pH). Using acid fertilizer will help, but not completely resolve this issue.
(2) Intense sun. You can solve for this with some version of shade cloth or sun covering.
(3) Low humidity. Combined with the sun, if you leave your tree outside on the wrong day, the leaves will crisp. If the Santa Anas are blowing you have to give it wind and sun protection - almost like a shadecloth tent - or the tree will burn up.

I tried many times to keep Japanese maples in Southern California, but was almost completely frustrated. I was able to keep a single Sango Kaku alive in a sheltered corner of my yard under shade cloth, but the tree never looked that great, and sadly, in the Fall the tree's leaves would dry up and fall off the tree without any autumn color.

I use a filtered water system for all my plants, I closed my shade blinds I have over the porch that protect my other maple that went into dormancy way late with our warm winter here. I definitely think I left it exposed too long in the mini heat wave we had with UV indexed at like 10 I think fried some leaves.. I have it pushed back out of direct light and closed my sun curtain so it gets a soft morning light and then indirect the rest of the day. We are moving pretty soon and I don’t know how much sunlight our new place will get so I am going to be experimenting with some grow lights, who knows might thrive will update with those.

 

[Wulfskaar]

I've kept my shishigashira J. maple alive for a few years now. Morning sun and/or dapples shade is what they need. I have serious doubts about grow lights being helpful.

Generally, late summer through fall, when the Santa Ana winds are blowing, we need to really protect them from that dry wind. Bonsainut is exactly right, if you don't protect them, the leaves will get dry and crispy and fall off before the spectacular fall colors that J. maples offer in fall.

This fall, I'll be really trying hard to protect mine from those winds because I really want to see the fall colors.

 

[Bonsai Nut]

I use a filtered water system for all my plants, I closed my shade blinds I have over the porch that protect my other maple that went into dormancy way late with our warm winter here. I definitely think I left it exposed too long in the mini heat wave we had with UV indexed at like 10 I think fried some leaves.. I have it pushed back out of direct light and closed my sun curtain so it gets a soft morning light and then indirect the rest of the day. We are moving pretty soon and I don’t know how much sunlight our new place will get so I am going to be experimenting with some grow lights, who knows might thrive will update with those.

One year I tried 10 different JM maple cultivars that were supposed to be "full sun" or at least more sun tolerant than normal. They looked great in the spring until about June - when the first Santa Anas blew off the high desert. Every single one crisped - even under shade cloth - and there was little I could do about it short of bringing the trees into my house. They rebudded as if I had defoliated them, and looked good for a month or two, until the next wind event, when they crisped and died... every one.

And when you say "filtered water" I want to make sure you understand what you need to do. You need to use either a water softener that uses potassium chloride pellets to refresh the element (not the sodium chloride ones) or a reverse osmosis unit - preferably with a deionizer. Get yourself some cheap pH test kits and a cheap TDS (total dissolved solids) meter. Test your water out of the tap, then test the water after you filter it. All California water districts are required to release annual water quality reports. Check your water district and see what you are "supposed" to be getting, and compare it to what you actually get. My water out of the tap would kill 3' koi if I added 6" of top-off to a 6' deep pond without treating it first. Untreated it was very high in chloramine... which is ammonia bound with chlorine. I would not recommend using that on a plant, but Cal is worried about showers and kitchen water - not what would be best for irrigation.

 

[Wulfskaar]

One year I tried 10 different JM maple cultivars that were supposed to be "full sun" or at least more sun tolerant than normal. They looked great in the spring until about June - when the first Santa Anas blew off the high desert. Every single one crisped - even under shade cloth - and there was little I could do about it short of bringing the trees into my house. They rebudded as if I had defoliated them, and looked good for a month or two, until the next wind event, when they crisped and died... every one.

This year, I'm going to try to put mine in a plastic greenhouse thing before the wind events. I might put a bucket of water in there to keep it more humid in there during the worst days.

I really hate Santa Ana winds, not just for how they crisp bonsai, but for how they cause so many terrible fires.

 

[jagboy69]

Hey Nut, can ya please explain the purpose of knowing total dissolved solids?? My water in west texas sucks big time! I installed a water softener and now I can get more than 2years out of a dishwasher! After the softener, I have an RO unit. So my water is actually drinkable. I also maintain a rain barrel to collect water for my plants. After a month or two of no rain, I'm looking at my barrel and while the water doesn't smell, i can't help but think I could be using better water for my maples. Whatcha think? Feed them RO water or install some goldfish in the barrel and hope I don't boil them on a hot day?

I have an endless supply of water on my property that I can't say how or why, but I tested the ph and it was way off the scale on the tester. So instead of paying my city a fortune for watering the bermuda, I use that water to flood the yard every few days. I have the greenest lawn in west texas, I'm really surprised no one has asked how or why when everything else out here is deadsville!

 

[hemmy]

Hey Nut, can ya please explain the purpose of knowing total dissolved solids?? My water in west texas sucks big time! I installed a water softener and now I can get more than 2years out of a dishwasher! After the softener, I have an RO unit. So my water is actually drinkable. I also maintain a rain barrel to collect water for my plants. After a month or two of no rain, I'm looking at my barrel and while the water doesn't smell, i can't help but think I could be using better water for my maples. Whatcha think? Feed them RO water or install some goldfish in the barrel and hope I don't boil them on a hot day?

I have an endless supply of water on my property that I can't say how or why, but I tested the ph and it was way off the scale on the tester. So instead of paying my city a fortune for watering the bermuda, I use that water to flood the yard every few days. I have the greenest lawn in west texas, I'm really surprised no one has asked how or why when everything else out here is deadsville!

TDS can indicate salts. As he mentioned earlier, pH and alkalinity (hardness) are also important. Theoretically, the RO system should remove the sodium or potassium from a water softener. But you might want to test it.

Rain barrels should be opaque to prevent algae growth and covered to keep out mosquitoes. Goldfish are pretty tough and can live shallow stock tanks.

What was the pH scale that it exceeded it?!

You might still want to test that water for irrigation suitability because there are soil amendments you can use to combat the hardness or salts.

 

[jagboy69]

Ever see those giant dark green recycle bins? YUP, collecting rain water is the best use for that thing that benefits THIS GUY! My endless supply tested over 10... Good point, I better pull a soil test on my bermuda. I ordered some more testers and will report back when they show up what I'm reading for pH and TDS.
Thanks!

 

[Yamamomiji]

Hmm, looks not like a sunburn as I have experienced, where the tips are most likely always affected too in drying out.
Seems somthing else, as suggested with watering ...

 

[Deep Sea Diver]

TDS won’t tell much about the hardness or softness of your water

TDS measures all dissolved solids, which includes hardness minerals (calcium and magnesium) but also other substances like salts, metals, and organic matter.

A water softener works by exchanging hardness minerals for sodium or potassium ions. Since these sodium/potassium ions also increase TDS, the TDS reading will be similar before and after softening, even if the hardness has been reduced.

A high TDS reading does not necessarily mean the water is hard, as the dissolved solids could be from other sources that don't contribute to hardness.

Carbonates in your local water quality report do indicate hardness or softness… and bonsai do not usually like hard water…. for local water not from a municipal system use hardness test strips or kits: These products are designed to specifically measure the calcium and magnesium content in water and will give you a direct reading of your water's hardness level.

While one cannot determine water hardness just by looking at its pH value, a higher pH level often suggests the presence of hard water, and vice versa

Cheers
DSD sends

 

[Jetson1950]

Not the expert here, but I’ve been able to keep all my maples alive and thriving in zone 9b Florida. To me, it doesn’t look like leaf scorch from the sun, but a transpiration issue with the heat and lack of humidity. If the temperature in their growing area is too hot without humidity, they can’t transpire properly and the leaves start drying out from lack of moisture. It’s different for me here because we have almost constant high humidity which helps protect them from drying out. I grow them in either 100% shade or under a 90% shade cloth. Another problem in your area as mine is lack of winter chill hours so they can have a good rest in the winter months. I’ve mentioned it before on other threads and it’s extra work, but mine all go into a frig for the winter to get their dormancy sleep. Once they come back out in the spring, the sun cannot touch their leaves or it will fry them. With the heavy shade cloth or full shade under trees, they stay cooler and are able to manage their transpiration and keep the leaves supple.