Fungus or something else?

[William Dinitzen]

Hello, just today when I went to look on my Chinese elm I noticed that the surface of the new leaves had become spotty. The tree has just started shooting quite aggressively about 1/2 weeks ago, as I had failed to care for it properly throughout the winter. Could anyone tell me what is going on, if its some kind of fungus, a lack of fertilisation or something else entirely?

 

[Shibui]

Yellowing foliage is far more likely to be nutrient deficiency but given you've only admitted to 'failure to care properly' and no details on how and what you have done it is hard to give a reasoned response.
What fertilizer and how often?
Soil type?
watering regime?
Pot size?
Assuming it is kept indoors given Denmark as location?
Some photos of the whole tree can often give experienced growers far more info than you'll even think to give

Definitely need far more info before I'd make any guesses as to cause.

 

[William Dinitzen]

Yellowing foliage is far more likely to be nutrient deficiency but given you've only admitted to 'failure to care properly' and no details on how and what you have done it is hard to give a reasoned response.
What fertilizer and how often?
Soil type?
watering regime?
Pot size?
Assuming it is kept indoors given Denmark as location?
Some photos of the whole tree can often give experienced growers far more info than you'll even think to give

Definitely need far more info before I'd make any guesses as to cause.

Hey I've been keeping it outside in a greenhouse since early February, however I only really got into bonsai this year which means that the tree had to endure quite abit throughout last fall, which is when I bought it, in addition to quite an inconsistent watering schedule (almost dried out a few times) it also didn't receive any fertilizer from September till march.
- Ive been fertilising with 5-5-5 organic cakes of some kind since march, as well as half a dose of liquid fertiliser in the beginning of may
- Im not sure about soil type , however I suppose overwatering could be a possibility as its been quite hot lately, which might have led me to go overboard on that front, however I try to only water when the top soil begins to look slightly dry.
- Pot is about 25 cm length

Ill attach some photos of the entire tree below
Ill try to be more thorough in my future posts

 

[Shibui]

Thanks for the extra info. It all helps to build a fuller picture and gives additional clues to any problem.

Organic cakes can take some time to have any effect as the ingredients need to decay in order to release nutrients but the liquid fertilizer should act a bit quicker. A single half strength dose may not be enough to overcome any nutrient deficiency so I'd keep giving it liquid fert every 2 weeks and hope I'm correct and that it makes a difference.
Just out of interest, what liquid fert are you using?

When it is hot more water is a good idea. Plants die much quicker from dehydration than from overwatering so I always err on the side of more than not enough in summer.

The soil looks like quite fine particle and dense. Most of us have switched to more open, larger particle soil mixes which gives better insurance against root rot but bonsai can be grown in almost any soil mix provided you can match care and watering to the soil and pot. Apart from the probable nutrient deficiency the tree appears to be doing well so your care has not been too poor so far. Consider changing the soil but best not to rush in and make wholesale changes just because some unknown person on the internet thought that was a good idea.

 

[William Dinitzen]

Thanks for the extra info. It all helps to build a fuller picture and gives additional clues to any problem.

Organic cakes can take some time to have any effect as the ingredients need to decay in order to release nutrients but the liquid fertilizer should act a bit quicker. A single half strength dose may not be enough to overcome any nutrient deficiency so I'd keep giving it liquid fert every 2 weeks and hope I'm correct and that it makes a difference.
Just out of interest, what liquid fert are you using?

When it is hot more water is a good idea. Plants die much quicker from dehydration than from overwatering so I always err on the side of more than not enough in summer.

The soil looks like quite fine particle and dense. Most of us have switched to more open, larger particle soil mixes which gives better insurance against root rot but bonsai can be grown in almost any soil mix provided you can match care and watering to the soil and pot. Apart from the probable nutrient deficiency the tree appears to be doing well so your care has not been too poor so far. Consider changing the soil but best not to rush in and make wholesale changes just because some unknown person on the internet thought that was a good idea.

Thanks for the reply, ill definitely be changing the soil next spring, however I don't think I would do it now when its gotten as hot as it is currently. Ill link a picture below of the liquid fertilizer im using, its just the standard one that you can get off amazon. Im going to give it a dose today

 

[Shibui]

It appears to be complete (has all major nutrients and trace elements) fertilizer so should be good. I was just checking that you were not using some of the products that don't have all necessary nutrients.
4:6:6 is not very strong so don't go for half strength with that one. Full strength mix and weekly applications to get any appreciable results I think. Maybe you can find something with higher N to give the tree an initial boost to cure the deficiency then back to or alternate with the Chrysal when it is happier.
Yellow NEW leaves is often a sign of Nitrogen deficiency in which case it needs a good boost with N to recover and grow well. A higher N fert will do that better than the low N Chrysal.

 

[William Dinitzen]

It appears to be complete (has all major nutrients and trace elements) fertilizer so should be good. I was just checking that you were not using some of the products that don't have all necessary nutrients.
4:6:6 is not very strong so don't go for half strength with that one. Full strength mix and weekly applications to get any appreciable results I think. Maybe you can find something with higher N to give the tree an initial boost to cure the deficiency then back to or alternate with the Chrysal when it is happier.
Yellow NEW leaves is often a sign of Nitrogen deficiency in which case it needs a good boost with N to recover and grow well. A higher N fert will do that better than the low N Chrysal.

Okay that's actually surprising to hear, since the guy who I bought the fertilizer from recommended me to use a lower nitrogen fertilizer for my elm, but that might explain the entire problem if it has a deficiency in that department. Thanks for clearing that up for me

 

[Leprous Garden]

Nitrogen is the nutrient plants use in the greatest amount. However, all nutrients must be present in some amount to allow for growth. (There are something like a dozen nutrients plants use for growth).

 

[Shibui]

Okay that's actually surprising to hear, since the guy who I bought the fertilizer from recommended me to use a lower nitrogen fertilizer for my elm, but that might explain the entire problem if it has a deficiency in that department. Thanks for clearing that up for me

As already mentioned, N is associated with plant growth.
In the early stages when we want lots of growth to boost trunk thickness and ramification of branches high N fert is a good choice.
Later, when the bonsai has a good trunk and plenty of nice branches we don't want so much growth so gradually change to lower N fert or just reduce quantity, strength or frequency of fertilizer application. All that presupposes a healthy tree. Yours does not appear healthy so needs a different nutrient regime. Possible N deficiency requires extra boost to overcome the deficiency and the low N won't give that.
The recommended fert is a good choice but just not for this specific case.
Using fertilizer is horses for courses. Different mix depending what you want to achieve. Unfortunately, bonsai is not mathematics. It is biology so often the answer is 'it depends' rather than black and white same answer every time in all cases.

 

[William Dinitzen]

As already mentioned, N is associated with plant growth.
In the early stages when we want lots of growth to boost trunk thickness and ramification of branches high N fert is a good choice.
Later, when the bonsai has a good trunk and plenty of nice branches we don't want so much growth so gradually change to lower N fert or just reduce quantity, strength or frequency of fertilizer application. All that presupposes a healthy tree. Yours does not appear healthy so needs a different nutrient regime. Possible N deficiency requires extra boost to overcome the deficiency and the low N won't give that.
The recommended fert is a good choice but just not for this specific case.
Using fertilizer is horses for courses. Different mix depending what you want to achieve. Unfortunately, bonsai is not mathematics. It is biology so often the answer is 'it depends' rather than black and white same answer every time in all cases.

Hi again, I just moved houses recently to live at my mothers house, and upon moving I noticed that any developments of the pigmentation and wilting of leaves has stopped, and new healthier leaves have begun shooting, so im wondering if it could be a water issue, from something in the pipes etc. and if the symptoms could fit something like that. Also, my father had been fertilising the lawn in the week when it happened, do you reckon one of these two could be the cause of the issue?

 

[Shibui]

Great to hear the problem is abating.
Water is one possible cause. Iron deficiency can cause chlorosis (yellow leaves). Iron is one of the nutrients that is made less available by increasing pH. In most areas the water authority doses water to keep pH a bit above neutral (pH7) to stop water pipes deteriorating. In some areas the water is naturally high pH so can come through the taps at pH 8 or 9.
We can counteract high Ph water for plants by using acidifying fertilizer. I believe significant areas of USA water supply is alkaline (high pH) so Miracid is an readily available fertilizer that helps counteract the water and bring pH back down closer to neutral (pH7).
Otherwise adding extra iron (iron chelates, iron sulphate, etc) is an alternative. Other nutrients can also be limited by high pH so you need to investigate all the ramifications of pH nutrient lock up if that's an issue.
You should be able to check local water authority testing on their website to find out a whole lot of info about the water you get.

Fertilizing the lawn is possible, but not likely, depending what he used. Usually lawn fertilizer will be high N and should make your trees grow faster. Some bonsai growers use lawn fert in the development stage to help trees grow faster.

 

[William Dinitzen]

Great to hear the problem is abating.
Water is one possible cause. Iron deficiency can cause chlorosis (yellow leaves). Iron is one of the nutrients that is made less available by increasing pH. In most areas the water authority doses water to keep pH a bit above neutral (pH7) to stop water pipes deteriorating. In some areas the water is naturally high pH so can come through the taps at pH 8 or 9.
We can counteract high Ph water for plants by using acidifying fertilizer. I believe significant areas of USA water supply is alkaline (high pH) so Miracid is an readily available fertilizer that helps counteract the water and bring pH back down closer to neutral (pH7).
Otherwise adding extra iron (iron chelates, iron sulphate, etc) is an alternative. Other nutrients can also be limited by high pH so you need to investigate all the ramifications of pH nutrient lock up if that's an issue.
You should be able to check local water authority testing on their website to find out a whole lot of info about the water you get.

Fertilizing the lawn is possible, but not likely, depending what he used. Usually lawn fertilizer will be high N and should make your trees grow faster. Some bonsai growers use lawn fert in the development stage to help trees grow faster.

Hmm it is hard to diagnose exactly what might be the cause as you say, but it just seems to me like the issue is a presence of something malicious rather than the absence of something constructive, since it happened so suddenly and spread through the entire tree killing most new growths. I suppose ill try fertilizing with distilled water for some time maybe, or would that just cause another set of problems?