Please help identify a "persistant" leaf problem: mineral, roots, fungus?

Would someone help me identify some problems on some new growth and old growth? the problem is mostly my maples, but I seem to have it on a cherry and a pear, and a fringe tree, too. Not all of my maples have "it". My soil mix is approx 80% sifted turface, 10% turkey grit, and 10% sifted pine bark fines. I defoliated a Trident forest and approx 5% of the new leaves have dark brown drying blotches and some of the leaves are curling. I water at least once per day, in the morning; and at dusk when I get home from work if they look dry. I wonder if I am watering too much. My soil mix is very free-draining. I have sprayed neem oil three times (approx two weeks apart) during the past 2 months. Here are the pics:

First is Acer rubrum (Red Maple, first year's leaves)


Trident Maple, new growth


Acer ginnala (Amur Maple)


Prunus (weeping cherry)


Sweetgum (Liquidamber)


Pyrus (pear)


Another Trident Maple


Thank you for any help or advice! Salut, Todd

The Acer rubrum has a common leaf spot/rust. It doesn't seem to be anything other than unsightly on any of mine, but I've found no way to prevent it. I just remove and destroy the leaves.

Most of the other leaf issues (except the sweetgum) look to me to be leaf dessication/burn -- because of the very, very hot days we've had here in the SE. My flowering quince and a couple of tridents have had it off and on this spring/early summer. Again, just remove the leaves; perhaps a bit more shade on the POTS (I have very little shade available where my trees are).

Liquidambar have few health issues. It could also be leaf burn, but it could also be the result of some other physical damage to the leaf.

Anyway, except for the minor probem with the red maple, I don't THINK any of these are disease related.

JimLewis wrote:The Acer rubrum has a common leaf spot/rust. It doesn't seem to be anything other than unsightly on any of mine, but I've found no way to prevent it. I just remove and destroy the leaves.

Most of the other leaf issues (except the sweetgum) look to me to be leaf dessication/burn -- because of the very, very hot days we've had here in the SE. My flowering quince and a couple of tridents have had it off and on this spring/early summer. Again, just remove the leaves; perhaps a bit more shade on the POTS (I have very little shade available where my trees are).

Liquidambar have few health issues. It could also be leaf burn, but it could also be the result of some other physical damage to the leaf.

Anyway, except for the minor probem with the red maple, I don't THINK any of these are disease related.

Thank you, Jim! I feel better and will keep tabs on them. I have to rethink my bench placement to allow for more shade for the sun "intolerants". i appreciate your time and reply. Salut, Todd

I am wondering if Maples particularly may be intolerant of Neem oil. Some other treatments cause distortion and browning of their leaves.

Maples (tridents especially) react badly to soap sprays. I've never used Neem, but if it IS an oil spray, the oil, plus the heat, could easily cause a problem. My only issue with that might be that I don't see that every leaf is involved. The oil heating up should cook every leaf that it touches. That's why you generally don't use oil sprays in summer -- even those whch claim to be OK in the heat. There's heat and then there's heat -- and we've been having the second kind here in the southeast for a couple of weeks now. It was 96 (F) here yesterday while I was mowing the pasture!!!!!!

Hi Todd.
I'm sorry to say I believe this is a fungus. It looks exactly like the problem I had here in Australia last season including the species. When I showed pictures of thios to Matt Ouwinga he recognised it as a fungus that he had seen on occasions before affecting Tridents but it is interesting none the less to see pictures of a disease the same as my trees have here in Australia!.
I had seen this fungus for a number of years but only learnt more about it since it hit bad with the right conditions last season.
Here is all I have learnt about it.
http://www.ausbonsai.com/forum/viewtopic.php?f=19&t=3927&p=44120&hilit

For either fungus or sunburn, I have found Dyna Gro ProTeKt to be very helpful. It is available at large nurseries. It is Potassium silicate & helps strengthen cell walls. If you can get Potassium silicate from a chemical supply company, it is said to be cheaper.
Iris

bonsaisr wrote:For either fungus or sunburn, I have found Dyna Gro ProTeKt to be very helpful. It is available at large nurseries. It is Potassium silicate & helps strengthen cell walls. If you can get Potassium silicate from a chemical supply company, it is said to be cheaper.
Iris

Thank you, Iris.

Thanks everyone for your suggestions! I really appreciate your help!

Wow I just logged on looking for clues to exactly this problem, and I'm not far from you Todd, in Maryland. My acers are the only trees suffering but they have it considerably worse than yours. New growth is especially susceptible on palmatums, but on the trident old growth is slowly dying back as well. All the new shoots are burning out on both types. It has been going on for over a month now, and the new growth the trident is trying to push now is tiny, and somewhat curled under, when it is still green at least.

I've been thinking fungus and alternating spraying with a neem oil and (I think) sulfur based solution. Honestly neither have seemed to help. It has been hot but the trees are in dappled shade, have not been allowed to dry out, and the landscape maples have not suffered from this.

Velodog2 wrote:Wow I just logged on looking for clues to exactly this problem, and I'm not far from you Todd, in Maryland. My acers are the only trees suffering but they have it considerably worse than yours. New growth is especially susceptible on palmatums, but on the trident old growth is slowly dying back as well. All the new shoots are burning out on both types. It has been going on for over a month now, and the new growth the trident is trying to push now is tiny, and somewhat curled under, when it is still green at least.

I've been thinking fungus and alternating spraying with a neem oil and (I think) sulfur based solution. Honestly neither have seemed to help. It has been hot but the trees are in dappled shade, have not been allowed to dry out, and the landscape maples have not suffered from this.

Hi Velodog2,
I'm inclined to think it is the heat. My landscape "everything" (including Jap. maples) are doing well. Also, I don't see any of these symptoms on the wild flora. I have two tridents which seem fine. I moved the maples to a more shady spot and hope this will help. My new growth on some of the trees are just as you described: tiny and curled under...and I was thinking "... at last the leaves are reducing... not in the way I intended..." Are you a member of PBA? Salut, Todd

Well I don't really believe that the problem is the heat, but I really don't know what it is which is why I'm here. I actually had it toward the middle of last August for the first time and if I remember right that was right about the start of a cool wet period. It essentially defoliated some of my palmatums by september, and that wasn't a great time of year to be doing that. Some of them struggled a little to come back this spring.

Not a member of any clubs except this one.

Hey Kevin, My red maple FREAKED out on neem oil treatment it seems. I used it lightly as a foliar spray once a week earlier in the spring and when it dawn on me that Neem may be the cause of the lack of vigour and funny looking leaves, i stop the neem treatment. the bugs got bad, but the growth exploded and is LUSH green at this time.

Hey Guys did you read the thread I linked. This is almost definatly the same thing I have been going through. The small leaves is another big telltale. Two trees can be sitting next to each other and one is affected and the other not. It can cause little trouble and go away as the growth picks up or it can stall the tree seriously to the point of death if given the right senario. Do not defoliate the more leaves you have on the tree the better the tree needs constant energy from it's leaves to fight the fungus otherwise the fungus will take the upper hand. Bravo fungucide has been the only thing that helps.
Here is that link agian
http://www.ausbonsai.com/forum/viewtopic.php?f=19&t=3927&p=43946&hilit=fungus+trident#p43946

This continues to come and go. The trident seems to be making some progress toward recovery. However new shoots on all maples are still quite prone to burning out. One palmatum is losing significant foliage, with some of the mature leaves turning fall colors. I don't think it will make it. Given that I don't know what it is I have not been treating them with anything.

Searches on the web make me think again that it is a systemic fungal problem. The closest description I can find of some of the symptoms is for verticillium wilt, although that doesn't seem to be an exact match. As I mentioned, the first time I noticed the issue was during a very damp cool period toward the end of last summer. This is pretty serious stuff, for my few poor maples anyway. I am going to be looking for new hard-core fungicides I think.