Am I worrying about nothing? Elm growing strong then sudden downturn

[SpencerCW]

My Chinese elm was growing strong up until two week ago when the inner leaves began to yellow and fall. I posted on reddit and they assured me that I have nothing to worry about and that sometimes elms lose their leaves. But I was also thinking of another possibility, overwatering/ poor drainage. I repotted the tree last winter but in my eagerness I used local dirt (east Tennessee red clay) mixed with organic top soil(basically fine mulch), a half a bag of organic potting soil and gravel. It takes about 3-5 seconds for water to drain out the bottom when top dry.

This elm has a little brother I didn't repot and it's inner leaves appear to be a faint yellow green but none have fallen. If this is a natural response will my elm lose every single leaf? If it is a drainage issue should I keep it dry from rain and keep it on controlled watering this season until winter when I can repot, change the soil, and do some root work? I've heard you're not supposed to prune the same year you repot so should I skip any trimming this year? Also why are the leaves down turned?

Any help would be appreciated. If I'm worrying about nothing let me know and I'll remove this post.

-thanks for your time
-spencer

 

[Shibui]

No problem pruning and repotting Chinese elm in the same year. No problem pruning and repotting Chinese elm in the same operation.

Unfortunately, it's hard to diagnose overwatering just from leaf symptoms. Your soil mix makes overwatering more likely but, not possible to be sure without checking the roots as symptoms of overwatering and underwatering are almost identical.
Dropping leaves in Summer is not a natural response. It is definitely a sign of some sort of stress but can be root problems (too wet), too dry, not enough sun, too much sun and probably more.

I'd probably try to manage watering a little better until you can repot.

Yellow leaves are often a sign of nutrient deficiency. The clay should help retain nutrients but, with regular watering, nutrients are still washed out of the soil. How often do you fertilise these trees?

 

[Jetson1950]

Also check the underside of the leaves very carefully for possible signs of sap sucking pests. Aphids, mealybugs, spider mites etc. They may have just recently found your plants.

 

[Bonsai Nut]

If I had to guess, it is a combination of bad soil that is compacting (no oxygen/holding too much water) and lack of fertilization. Even with the heat we've been having, your elms should be a dark glossy green color. The leaves should also be stiff, held outright, and not limp and drooping.

I would pull the tree out of the pot and check to make sure you aren't choking the roots. Make sure there are enough holes in the bottom of your bucket. A quick bandaid (without root work) would be to pull out the tree, place a 3" drainage layer of pine bark mini nuggets (with nothing else mixed in) and then put the tree back in the pot on top of the nuggets. Also, water with water soluble Miracle Grow (not time release pellets).

 

[SpencerCW]

The soil was very compacted. I added pine bark to the bottom and stabbed all around the dirt with a piece of wire coat hanger to break up the soil. I also got stick fertilizer but I see here you recommended liquid so I'll return it tomorrow.

 

[PA_Penjing]

Looks like you are getting the fungal infections on yours that are almost guaranteed in our part of the country. I have not figured out how to avoid them but it looks like @Bonsai Nut has. I have tried to be so careful and cannot keep mine from getting black spot at some point. the only thing I haven't tried is a super fast draining soil, like something you'd use for pines. I'm thinking that's the key? I gave up on the species because I didn't want to infect my native elms AND I can't acquire material around me that isn't already infected/ailing. But I agree with the advice, if I were to try the species again, drainage and well timed watering would be paramount. But I could be wrong again... some species just don't jive with me, while others flourish

 

[Bonsai Nut]

Looks like you are getting the fungal infections on yours that are almost guaranteed in our part of the country. I have not figured out how to avoid them but it looks like @Bonsai Nut has.

Inorganic soil.

 

[rockm]

The soil was very compacted. I added pine bark to the bottom and stabbed all around the dirt with a piece of wire coat hanger to break up the soil. I also got stick fertilizer but I see here you recommended liquid so I'll return it tomorrow. View attachment 606651

IMO The soil looks extremely dry at the bottom and probably all through the interior of the rootball from what the photo shows The soil looks to be dry enough that it has become hydrophobic—it repels water forcing it down the sides of the pot instead of soaking through. The interior roots could be dying off. Fine field soil n a container is problem for this reason.

I’d submerge the entire root mass in a bucket of water for half an hour. Then let it sit to drain for a while. See what happens. Might perk up a bit.

In any case this should be barefooted and repotted next spring you’re going to have to be cautious in watering until then

 

[SpencerCW]

Is the black dot then yellowing of a leaf caused by fungus? I have been treating with neem oil weekly.
Anyway, I believe I have a plan for my trees.i plan to repot all my trees into pond baskets. Since all my trees are still in development Im gonna grow them in organic potting soil amended with perlite. Does this sound like a better setup than what they're in currently? I started my journey into bonsai last year with a couple elms from my dad. I wanted to give them the best chance with what l had but messed up with the soil.

I really hope my big elm doesn't die! It put in a lot of good growth this year. Thank you guys for helping a newcomer learn.

Looks like you are getting the fungal infections on yours that are almost guaranteed in our part of the country. I have not figured out how to avoid them but it looks like @Bonsai Nut has. I have tried to be so careful and cannot keep mine from getting black spot at some point. the only thing I haven't tried is a super fast draining soil, like something you'd use for pines. I'm thinking that's the key? I gave up on the species because I didn't want to infect my native elms AND I can't acquire material around me that isn't already infected/ailing. But I agree with the advice, if I were to try the species again, drainage and well timed watering would be paramount. But I could be wrong again... some species just don't jive with me, while others flourish

 

[PA_Penjing]

Yes it is fungal. I know it as "black spot disease" but I'm sure there's a more scientific name. it won't kill the elm quickly it takes many many years of prematurely shedding and weakening the tree. But eventually it will make the tree very sparse, ugly and eventually dead. I have never grown prebonsai in pond baskets so I can't help there. Based on Bnut's soil advice, and my years of failed attempts, a fast draining medium is imperative

 

[nuttiest]

How did you get moss to grow there on outside, clear pot? It could be a kokedama!

 

[SpencerCW]

How did you get moss to grow there on outside, clear pot? It could be a kokedama!

That's what the soil looked like when I pulled the tree out of the five gallon bucket. I'm considering an emergency repot into organic potting soil and perlite but I'm worried about putting more stress on an already stressed tree. So I'll probably just wait and see. I'm also gonna keep them in shade on my front porch until I can build some sort of shade tent.

 

[nuttiest]

potting soil when I pulled the tree out of the five gallon bucket.

So the buckets let light in, maybe elm roots don't like that. Do you have a nursery can with 4 good size holes on the sides? I think gently slip potting is fine (because it has to be) I wouldn't put anything under that mud except a clay pot. It does look dry though
I keep drying out some elms, because they don't announce when they are getting ready to drink more water than everything else, and before I know it They are dry and sometimes lose all the leaves, only to releaf in a couple of weeks with fine new growth. I can only get away with that once on the same tree.