AusBonsai

Hey all i have a batch of chinese elms about 4 months old and one by one are showing the same symptoms.

I was thinking they were nutrient deficient but as its progressed iv wondered it may be a fungal disease.. it affects the bottom half of the tree and slowly works upwards.

first signs are these dark dots on the leaf edges which is followed by yellowing around the same area




the spots and yellowing progress inwards before the leaf drops off



anyone know what is going on here? any advice or ideas is appreciated

I did read someone talking about these sorts of issues (inward) as you call it..
As apposed to losing leaves from the edges in..

I believe someone should be able to shed some light on this for you soon.

Good luck.

bilbo baggins wrote:Hey all i have a batch of chinese elms about 4 months old and one by one are showing the same symptoms.

I was thinking they were nutrient deficient but as its progressed iv wondered it may be a fungal disease.. it affects the bottom half of the tree and slowly works upwards.

first signs are these dark dots on the leaf edges which is followed by yellowing around the same area




the spots and yellowing progress inwards before the leaf drops off



anyone know what is going on here? any advice or ideas is appreciated

Hi bilbo,
I'm not sure where you live in Australia. Being Chinese Elms they will loose their leaves. Are the trees in a sunny position? Do you have a fertilizer regime for the trees? How wet are are the trees, and do you have good drainage?

Regards Ray

I have actually gotten a similar issue with my chinese elm as well, although the leaves on mine dont seem to have the black spots. Do the leaves on yours go hard once they turn yellowish? Mine started well before winter, the soil is moist and i fertilise every two weeks or so.

Ray M wrote: Hi bilbo,
I'm not sure where you live in Australia. Being Chinese Elms they will loose their leaves. Are the trees in a sunny position? Do you have a fertilizer regime for the trees? How wet are are the trees, and do you have good drainage?

Regards Ray

I'm in Melbourne but the plants were started from seed and have been growing under high output t5s. the plan is to keep them growing indoors through winter and hopefully they have enough energy to keep growing through the spring and summer before going dormant for the first time next winter.

They get fed but it isn't much of a regime at this point, they have had a few drinks of seasol after transplant and were already showing some signs of over feeding so i cut right back and over the last couple of months have been getting macro and micro nutes fed roughly every 1 - 3 weeks ( have been moving and still not very organised).
so they are getting plenty of food but may be getting nutrients locked out with a bad ph (no idea what happened to my ph/ppm tester i packed so i cant check at this time).

The medium has a fair bit of turface mixed in so it drain well, I wait about 3-5 days until the pots are light and almost completely dried out before I water.

I think I have it narrowed down to either a nutrient lock out or a fungal disease. I'v never had to deal with the latter so im not even sure if these are definite symptoms.

I think I will try find my ph meter and check what the ph of the water at this new house is and get that right if its out first and if that isn't/ doesn't fix the problem ill strip off any affected leaves and use a fungicide.

can any recommend a good easy to find fungicide?

My first thought is not enough water. If the medium is draining well and you have them under grow lights I would have thought daily watering would be required ?

Bougy Fan wrote:My first thought is not enough water. If the medium is draining well and you have them under grow lights I would have thought daily watering would be required ?

That would make sense. sometimes its 50/50 if i should water or not and I usually choose not to and let the pots dry out almost completely. A few have been left to dry out a bit to long and have had droopy leaves when I did go to water, so there has defiantly been moments of drought for them.i may have been letting them dry out to much more often then i thought and could be why it seems like its constantly progressing. I will keep the medium from drying all the way out and water probably about every second day and see if that helps

I would think daily watering - and I would presume with grow lights these won't go dormant ? Not sure how that will affect the tree - I think they need to go dormant ?

This is what my PJ has, no amount of change in watering/fert techniques is solving it.

Dear Mr Baggins, I'd suggest that you water more old chap. With such a free draining mix your preciousies should be fine. Not sure about the black spots. Could be a fungal thing, so you could treat for that, but, if you are not watering well, your trees will be continuously stressed, and this can make them more susceptible to other problems. You should lose all the leaves come spring for a new crop.

Bougy Fan wrote:I would think daily watering - and I would presume with grow lights these won't go dormant ? Not sure how that will affect the tree - I think they need to go dormant ?

yes if I was keeping them indoor for good they would still need cooler conditions to simulate winter to kick in a rest period. I have read that most deciduous tree can last a couple of seasons without a dormancy if the conditions allow before it harms them. these will be going outdoors permanently in spring so fingers crossed they go strong until next winter, I am trying the same with a few different maples

Andrew Legg wrote:Dear Mr Baggins, I'd suggest that you water more old chap. With such a free draining mix your preciousies should be fine. Not sure about the black spots. Could be a fungal thing, so you could treat for that, but, if you are not watering well, your trees will be continuously stressed, and this can make them more susceptible to other problems. You should lose all the leaves come spring for a new crop.

haha yes ill be sure not to fear overwatering the preciousies any more and ill look into a good fungicide and see if that helps with the plague. May your fields remain tilled Mr Legg

Hi bilbo,
The other fellows have raised a number on good ideas. The following may repeat some of these things, but here are some thoughts.
1/ You are not watering enough.
2/ Try the following fertilizer regime. Get some Seamungus and some Dolomite Lime. Seamungus is produce by Neutrog and Dolomite Lime is produced by Richgro. Put a reasonable sprinkling of Seamungus on the soil, then sprinkle Dolomite Lime on top of the soil. The Dolomite Lime only needs to just be a sprinkle. Now hose the tree until the Dolomite Lime washes through. Eventually the Seamungus will break down and will virtually disappear. When this happens you can repeat the process every couple of months or so.
3/ I am wondering if you are forcing the trees and not letting them go through their normal cycle.

Regards Ray

Ray M wrote:Hi bilbo,
The other fellows have raised a number on good ideas. The following may repeat some of these things, but here are some thoughts.
1/ You are not watering enough.
2/ Try the following fertilizer regime. Get some Seamungus and some Dolomite Lime. Seamungus is produce by Neutrog and Dolomite Lime is produced by Richgro. Put a reasonable sprinkling of Seamungus on the soil, then sprinkle Dolomite Lime on top of the soil. The Dolomite Lime only needs to just be a sprinkle. Now hose the tree until the Dolomite Lime washes through. Eventually the Seamungus will break down and will virtually disappear. When this happens you can repeat the process every couple of months or so.
3/ I am wondering if you are forcing the trees and not letting them go through their normal cycle.

Regards Ray

cheers for the feedback

I do have a bag of dolomite lime, I will top dress with it next time I water. Do you use this as a ph buffer or for the cal/mg or both? I ask because I also have epsom salts if you are thinking its lacking cal/mg

yes the trees sprouted in Autumn. I brought a lot of seeds and thought I would try a bunch of them to get an idea of the germination rates and they were pretty good with the elms. I figured id may as well atleast experiment with the seeds that germinated see if they can grow for there first year without dormancy. I stil have a lot stratifying in a fridge that I will be sowing just before spring

Hi bilbo,

I do have a bag of dolomite lime, I will top dress with it next time I water. Do you use this as a ph buffer or for the cal/mg or both? Yes, it does balance the ph but the tree gets a lot more from it as well. I ask because I also have epsom salts if you are thinking its lacking cal/mg

yes the trees sprouted in Autumn. I brought a lot of seeds and thought I would try a bunch of them to get an idea of the germination rates and they were pretty good with the elms. I figured id may as well atleast experiment with the seeds that germinated see if they can grow for there first year without dormancy. I stil have a lot stratifying in a fridge that I will be sowing just before spring. Good on you for trying some experiments. It can be good fun and you can learn a lot.

Regards Ray