AusBonsai

Hi All,

could anyone please help to identify what could've caused these burn on my tridents as well as japanese maples? is it sun burn or fertiliser burn or perhaps something else? it only happens on new grow on tip. so I'm abit puzzled.
I've got some really course inert (2 part diatomite, 1 part zeolite, 1 part small nugget bark), so my fertiliser routin is quite aggresive(top dressed with lots of DL, and full strength powerfeed fortnight alternate with seasol) and the trees are under a huge jacaranda tree, so it should be filter light only.




Thanks

My guess is dry winds. Have you had a hot dry wind in the past week in your area? My Japanese maples do the same when after a hot dry wind (northerly here in Adelaide) but Trident maples are a bit hardier. Haveing said that I have a few brown tips on some of my Trident leaves, but my Japanese are worse. We had 3 or 4 hot days of 38-42 odd degrees here last week and my trees didn't like it one bit. Only thing you can do is place a big bowl of water nearby to increase humidity, or you could always defoliate if you know a dry spell is coming. And water morning and night!!!! I have my trees in a very similar mix to you, and I fertilise every Sunday with full strength liquid ferts. The only other thing it could be is if you are watering during the day (on the foliage) and the water droplets are acting as magnifying glasses. But I don't think that is the case. I have to say, I am only talking from my own experience which is only 2 summers so far, and from what I have learnt from members of my club with maples. I'm sure someone else will chime in if they can add anything.
Hope that helps??

It lookswto only be the newest leaves that have copped it (and they are always the most fragile).
I agree that even in the shade the wind burns maple leaves and it happens to a mature maple tree in my rear
ct. yard every year.
I know you said that this wasn't the reason for the burnt leaves Luke...and I am not having a go at you...

Luke308 wrote:The only other thing it could be is if you are watering during the day (on the foliage) and the water droplets are acting as magnifying glasses. But I don't think that is the case.

...it is just that I have read this in a few bonsai books etc and I think it is so not possible. Just my opinion as I have never experienced this and I have misted and watered fresh new leaves that are still forming in 40 degree plus days in full sun.
Cheers, Dario.

Hi Cutejai

I'm also located in Sydney and have had similar browning on my trident maples. I found this in the last couple hot days that we had recently and since the weather has cooled a bit they have not got any worse

If you could let me know how yours go over the next week or so I would be appreciative as I am a realities new commer to the word of bonsai and maples especially

Cheers
Matt

Dario wrote:It lookswto only be the newest leaves that have copped it (and they are always the most fragile).
I agree that even in the shade the wind burns maple leaves and it happens to a mature maple tree in my rear
ct. yard every year.
I know you said that this wasn't the reason for the burnt leaves Luke...and I am not having a go at you...

Luke308 wrote:The only other thing it could be is if you are watering during the day (on the foliage) and the water droplets are acting as magnifying glasses. But I don't think that is the case.

...it is just that I have read this in a few bonsai books etc and I think it is so not possible. Just my opinion as I have never experienced this and I have misted and watered fresh new leaves that are still forming in 40 degree plus days in full sun.
Cheers, Dario.

Did you read I said it was most likely the wind? Which you also stated? I was only offering other possibilities from what I have read in Bonsai books and Horticultural texts. I didn't say I agreed with it, nor say this was the reason my maples had suffered, I was only sharing a possibility.

Thank you all for some great input, I guess it's more likely the cause of wind burn from the last few hot days, it's rather annoying to see this happening when you try to fatten the tree up and allow it to go rampage, when seeing the new flush coming up, you know the tree is extending the branches hence fatten the trunk, but after such tip burn, it's gonna stop for a while before pushing new grow again. what a waste of energy on those new tips.

my other suspect is the mix doesn't hold enough water or dry out rather quick for this species even watering twice a day, might need to add 1 part of coco peat to one or 2 pots to see how they go. because they were doing great last year in a more organic mix.

Cheers

Wind burn is something we in Australia do have to suffer, we can however minimize the burn by protecting the roots. If the roots are cool there is some resistance, to this happening.
The Japanese have put Sphagnum moss in the mix for many years, I have also done this, and also on the top of the soil, it does minimise it. The other thing is build a wind break, by staggering the line of breaks it slows the wind.

I have just started growing them again, and have created a wind break by putting other plants near them to diffuse the wind.

DL will send the soil Alkaline and not many plants tolerate it. Rain drops/water on the leaves acting as a magnifying agent is one of the great myths of gardening.

Salts from fertilisers will cause this to happen occasionally. Usually what you have is wind and as I said a problem we have to learn from others how to try to stop it.

In 2001 Ernie Kuo from California USA, was here in the West he was the one that told us about the importance of keeping the roots cool. Their climate is the same as ours, and very similar to South Australia. So cool roots is the way to go, as there are some very nice Japanese Maples and Tridents in California.

Cheers Pup

Luke308 wrote: Did you read I said it was most likely the wind? Which you also stated? I was only offering other possibilities from what I have read in Bonsai books and Horticultural texts. I didn't say I agreed with it, nor say this was the reason my maples had suffered, I was only sharing a possibility.

Hi Luke yeah I did read what you wrote, and I was agreeing with you that it was most likely wind burn!
When you wrote...

Luke308 wrote: The only other thing it could be is if you are watering during the day (on the foliage) and the water droplets are acting as magnifying glasses. But I don't think that is the case.

...I noted that you did not attribute the leaf damage to this (and that you were only sharing another possibility ), and I never stated that you subscribed to this belief.
I clearly stated that I wasn't having a go at you, but that I had also read this in books and that I hadn't found it to be true, that was all.
I don't see what the problem is, but was a little surprised by your response.
Cheers, Dario.

Thanks for the tip on keeping the roots cool Pup.....I'll try it out and let you know how I get on

Cheers
Matt

Thanks Pup, I think cool root might also be the key here. last year they were all in normal pot, and this year I've switched all into large shallow pot which might not bury the root high enough. will try to top up some more inert and see if that helps.

Cheers