Don’t be Dutch Elm Disease 🤞

[DonovanC]

I have a few American Elms, and pretty much all of them have pretty crappy looking leaves. They all started the season great, then started getting burnt looking and a little yellow (some more than others). Some look almost completely fine while others are quite ugly. But all have at least some burnt, gray-white spots. They seem otherwise fine. I’m honestly hoping that this is due to my less than ideal watering. I’ve since gotten into a better watering routine and they all have new growth which looks fine.
I’m assuming fungus...
Any ideas?
Also I had an issue with scale, and the occasion - those little fuzzy white bugs that leave fuzzy white stuff on the trees - but I’m treating and haven’t seen any scale and only occasional other pests.
Sh

 

[Hack Yeah!]

Mealybug sounds like the pest you are describing

 

[DonovanC]

Mealybug sounds like the pest you are describing

I thought that but second guessed myself - but regardless, I only see them occasionally. So I don’t think they’re the problem.

 

[Smoke]

Treat with fungicide weekly for a month. Then bi-monthly after that. Dilute fungicide to half and keep it up all year. Alternate product twice a year and you will have no more problems.

 

[Shibui]

Mealy bugs also live on the roots where you can't see them. Only some come upstairs for a holiday in the sun.
Some of that damage looks like it could be nutritional, some looks like fungal problem and some could be lack of water. New leaves is encouraging. Good sunlight helps reduce fungal problems and most tends to be seasonal so may disappear for a while. Fungicide can help when conditions are conducive.
Healthier plants also cope better with most infections so water properly and fertilise regularly.

 

[rockm]

Your elms are far far too small to be candidates for DED. The disease is spread by bark beetles that burrow under the bark of elms. Your trees are too small to be of any interest to those beetles. Additionally, those pests tend to stay in the canopies of large trees and not near the ground. Again, your trees are of no interest to them, if they've even noticed them.

This is a fungal problem--the insects are opportunistic, feeding on a weakened tree. I would go with the fungicide. I'd also watch watering closely. The soil looks heavy and a bit wet. Elms don't like "wet feet" and those conditions can promote fungal problems.

 

[GGB]

Rockm beat me to it. Ditch elm disease is a big tree disease. You aren’t likely to deal with it unless you’re going for a huge finished tree and live near infected elms at the time

 

[DonovanC]

Rockm beat me to it. Ditch elm disease is a big tree disease. You aren’t likely to deal with it unless you’re going for a huge finished tree and live near infected elms at the time

That’s all I wanted to hear lol

 

[DonovanC]

Your elms are far far too small to be candidates for DED. The disease is spread by bark beetles that burrow under the bark of elms. Your trees are too small to be of any interest to those beetles. Additionally, those pests tend to stay in the canopies of large trees and not near the ground. Again, your trees are of no interest to them, if they've even noticed them.

This is a fungal problem--the insects are opportunistic, feeding on a weakened tree. I would go with the fungicide. I'd also watch watering closely. The soil looks heavy and a bit wet. Elms don't like "wet feet" and those conditions can promote fungal problems.

Thanks! I assumed fungus as well, but I hadn’t suspected wet feet as I actually feel like I’ve underwatered a lot this, the substrate is fairly free-draining - but then again, we were having a lot of rain when the problem first appeared so that makes sense. I had a similar issue last year. The substrate it turface, perlite, and compost (40:40:20). Also, like like Shibui mentioned, I think nutrition has a part in this. Like watering, I also hadn’t fertilized quite as well. My newborn has done a good job of keeping me preoccupied, so finding a new rhythm has been a process.
Thanks for the input!

 

[DonovanC]

Mealy bugs also live on the roots where you can't see them. Only some come upstairs for a holiday in the sun.
Some of that damage looks like it could be nutritional, some looks like fungal problem and some could be lack of water. New leaves is encouraging. Good sunlight helps reduce fungal problems and most tends to be seasonal so may disappear for a while. Fungicide can help when conditions are conducive.
Healthier plants also cope better with most infections so water properly and fertilise regularly.

Thanks, I’ve been using diluted dish liquid (not nearly as often as I should), and I use diluted peroxide for fungal treatment which seems to have been successful in the past. I’m a little leery of fungicides, I used copper fungicide at the beginning of the year and it definitely seemed to kill off all my new buds - my Japanese maples still haven’t quite recovered. Smoke mentioned diluted fungicide for upkeep, perhaps that’s the avenue.

 

[DonovanC]

Treat with fungicide weekly for a month. Then bi-monthly after that. Dilute fungicide to half and keep it up all year. Alternate product twice a year and you will have no more problems.

Hey thanks! Any tips on proper application? I used copper fungicide (I don’t recall specifically which one) at the beginning of the year, mainly because I had Cedar Apple rust, but I used it on my maples and elms as well - I had a devastating bout with fungus last year and lost several maples - anyways, maples has just started to lead out and after using the fungicide all the forming buds died. So I’m a little anxious about how to go about using it.
Thanks again!

 

[WNC Bonsai]

I went through this with my trees lst year so this year I decided to get proactive. I began in the spring with an application of Bonide systemic insecticide. One application is enough for a year and that has kept most insects at bay. Also last year I had the usual leaf spot and yellowing problems so this spring I started with Bonie Infuse systemic fungicide then a month later applied Daconil, then a month after that Mancozeb, and next will go back to Infuse. Alternating the fungicide prevents the fungi from developing immunity. This year no leaf spot or insect issues to speak of. My landscape plants on the other hand are showing the usual damage from bugs and fungi with mildew the current problem. For the fuzzy white bugs look up cotton leafhopper, right now is the time for them. They leave a fuzzy white patch on the stems and if you go to touch it the bug jumps off.

 

[Dan92119]

Thanks to @DonovanC for asking these questions about American Elms. I have some small American elm trees last year the leaves got eaten up by bugs. They are so soft compared to Chinese elms! This year I used Bayer 3 in 1 for roses on the trees. They look great. I didn’t know if the Beatles that carry DED don’t go for little trees. I don’t even know if the Beatles and DED is in San Diego. Just thought better safe than sorry. Thanks to everyone for the information!

 

[Smoke]

Thanks to @DonovanC for asking these questions about American Elms. I have some small American elm trees last year the leaves got eaten up by bugs. They are so soft compared to Chinese elms! This year I used Bayer 3 in 1 for roses on the trees. They look great. I didn’t know if the Beatles that carry DED don’t go for little trees. I don’t even know if the Beatles and DED is in San Diego. Just thought better safe than sorry. Thanks to everyone for the information!

I think the Beatles are from Liverpool. The beetles you speak of may be in San Diego.

 

[Dan92119]

I think the Beatles are from Liverpool. The beetles you speak of may be in San Diego.

It’s stupid autocorrect! I wasn’t going to fight it!