same strange browning of leaves on different plants

[Naimul]

Hi,

Ive been noticing that several of my plants are getting the same kind of browning of the leaves. 3-4 weeks ago i topped up all my pots with this blood and bones mix which contained a few other things, so it wasnt just plain blood and bones. the strange thing is, it is only affecting 5 out of maybe 10-12 plants.
I have attached photos of the leaves. im stumped what it could be, the blood and bones top up is the only variable between these plants, maybe i overdosed for the amount of soil and plant size?

The browning isnt so visible on the trident since it got it first and i cut them off thinking it was just dried out leaves. it seems to have affected the peace lily and the chinese elm the most.
All plants were healthy prior to this, the main reason for the blood and bones top dressing was because i was mainly using chemical ferts, and figured some organic stuff would be good for them
this also started prior to the recent hot and wet weather, but the chinese elm ive noticed started sometime inbetween.

What really surprised me is that none of my other trees are displaying anything like this, they are going along as per usual.

Any ideas what it could be ?

[longd_au]

Looks like burn to me. The trident looks healthy.

[matlea]

Could be burn with the few hot days we have had recently

[Naimul]

i would have thought the same but this started, at least on the umbrella, peace lily and the trident, before the recent hot weather.

[treeman]

It's difficult to diagnose these kinds of things without knowing more details about what you're doing. Have they dried out at any stage? Are you sure? (Sometimes the top of the mix looks wet but further down the mix has become hydrophobic and no amount of watering will solve the problem without wetting agents) Check by pulling them out and looking at the roots after watering. If this is a problem, soak them in a bucket of water with some ''wetta soil'' added.
Are they water logged?...Check
Adding fertilizer to dry soil will make things much worse. How much Blood and bone did you add? What else was in it?
Are they always in full sun? The peace lily should certainly be in shade.
Dry soil and full sun is also a recipe for disaster.
You need to look at all these things and whatever else you can think of to discover the cause.

[Naimul]

It's difficult to diagnose these kinds of things without knowing more details about what you're doing. Have they dried out at any stage? Are you sure? (Sometimes the top of the mix looks wet but further down the mix has become hydrophobic and no amount of watering will solve the problem without wetting agents) Check by pulling them out and looking at the roots after watering. If this is a problem, soak them in a bucket of water with some ''wetta soil'' added.
Are they water logged?...Check
Adding fertilizer to dry soil will make things much worse. How much Blood and bone did you add? What else was in it?
Are they always in full sun? The peace lily should certainly be in shade.
Dry soil and full sun is also a recipe for disaster.
You need to look at all these things and whatever else you can think of to discover the cause.

of course, what was i thinking .

For sun, the affected plants get roughly 1/4 to 1/2 a day worth of full sun.
As for how much blood and bones i used, those in plastic pots are roughly 75mm in size and the ones in clay pots i suspect are the size you would use for large-ish sized shohin trees. I added roughly a handful to each pot. The trees that get anywhere between 3/4 to a full day of full sun, i applied about the same amount of blood and bones, and they were in similar sized pots, but dont show the same signs as the affected.

I dont believe they have dried out between watering, i made sure to add a bit more potting mix when i last repotted as i know i tend to forget sometimes, and lately i have been very vigilant as to when and how much i water.

i have been keeping track these last few days while it has been cooler, and i have washed off some of the blood and bones from the surface. I think it might have been a combination of the blood and bones + hot days. the heat probably exacerbated the potential overdose of blood and bones perhaps?