Last fall I planted an assortment of trees, now that they're all leading out I've noticed an issue. The bulk of them have developed brown spots on the leaves. The spot goes through the thickness of the leaf. A quick google search showed this can either be a bacterial or fungal infection. I've noticed no "rust" or "powder" associated with the spots. Likewise, this has affected apples, plums, pears, and cherries. Given such a wide assortment I would almost think it couldn't be bacterial. I fully expected it on the cherries as I've yet to find a wild cherry tree in our area without them, but the others came as a surprise.
Are there other ways I can narrow down and diagnose the problem? For that matter can anyone fathom a good guess on what it is? If so, what can I do to solve it? Finally, how dangerous is it to the trees?
I wouldn't worry much if this wasn't the first real growing season for the trees. I should note it hasn't affected my maple tree, pawpaws, peach (that I can tell thus far), or almond.
With out photos, it certainly sounds like Black Spot, a disease usually thought of to be found only on roses, but it just isn't so.
Black spot (Diplocarpon rosae) can attack any fleshy leaves and or stems when conditions are right. It could also be Anthracnose which I will talk about after the Diplocarpon rosae.
Getting rid of black leaf spot must be a two-pronged attack.
Because its spores travel on the wind and plash from leaf to leaf during watering, treating black leaf spot should be first on your agenda.
There are several good fungicides on the market, several of which claim to be organic.
They come in handy bottle sprayers, but if your garden is large, you might want to buy it as a concentrate to mix in your tank sprayer. I consider this the last ditch approach, since I hate to have to use any sprays of this type before trying other things.
Neem oil is an acceptable alternative for treating black leaf spot.
It’s an oil pressed from an evergreen tree.
It’s all natural and has shown some remarkable results as an effective garden fungicide.
For those of you who prefer Grandma’s solutions to garden problems,
try this: Mix one heaping tablespoon of bicarbonate of soda (baking soda) into a gallon of water for your sprayer.
Add a dash of horticultural oil or horticultural soap and Voila!
You have a method of treating black leaf spot that works by changing the pH on the leaf surface to one the fungus can’t survive.
The oil or soap makes the solution stick and the cost is around four cents a gallon.
The next step in getting rid of black leaf spot is prevention and maintenance.
Inspect your garden regularly in the spring.
Black spots on plant tissues will spread quickly.
Start preventative spraying before the temperatures hit sixty.
Read the label directions for the method you choose and follow it closely.
For Grandma’s recipe, a light weekly dose should be sufficient.
Continue spraying until temperatures are hot enough to get rid of black spot fungus without.
Avoid watering your plants on cloudy days.
Bright sun and good air circulation are essential for getting rid of black leaf spot.
During an outbreak, all affected debris should be disposed of.
It may not be ideal as far as looks go, but affected plants should be cut back, and in the fall every bit of garden debris should be bagged and thrown away or burned.
The spores can overwinter on plant material, but can’t survive in bare soil.
The good news is that black spot fungus rarely kills the host plant.
Getting rid of black leaf spot takes a lot of diligence, but in the end, the rewards are worth it.
Anthracnose diseases of hardwood trees are widespread throughout the Eastern United States.
The most common symptom of these diseases is dead areas or blotches on the leaves.
Because of the brown and black, scorched appearance of the leaves, the diseases are sometimes called leaf blight.
The symptoms vary somewhat, depending on the host. Under certain conditions, the whole leaf dies and falls prematurely.
On some tree species, the diseases may also damage twigs, shoots, buds, and fruits.
Repeated defoliation reduces growth, weakens the tree, and increases its susceptibility to attack by other pests and to winter injury.
These diseases are caused by several closely related fungi, plants that reproduce by means of spores - the fungal equivalent of seeds.
Spores spread the disease when moved by wind, rain, or mechanical means from one host to another.
Anthracnose fungi attack numerous hardwood species, including ash, basswood, birch, catalpa, elm, hickory, horsechestnut, London planetree, maple, oak, sycamore, tuliptree, and walnut.
Although anthracnose diseases have been found wherever these trees grow, not all hardwoods are equally affected.
The diseases are particularly severe on American sycamore, white oak and other oaks in the white oak group, and black walnut.
Sometimes, these species are almost completely defoliated; and on black walnut, nut production is affected.
Infections are frequently found on other oak species, including scarlet, black, red, and southern red oaks; but the red oaks appear to be less susceptible than the white oaks.
Pin oak, swamp chestnut oak, bur oak, and London planetree are only occasionally infected by the fungi.
Symptoms on infected leaves range from tiny dead spots to large circular or irregular dead blotches, depending on the tree species.
Dead areas are black, brown, or purple. On sycamore (cover photo) and maple, infected areas are often found along the veins and midrib of the leaf.
The dead areas may merge until the whole leaf dies.
Infection in the early spring may turn the leaves black so that they resemble leaves damaged by frost.
If they are not killed by the fungi, young leaves may become distorted by the unequal growth in healthy and infected parts. Distorted leaves are common on oaks.
When severely infected, trees may lose their leaves.
But if defoliation occurs in spring or early summer, a tree will usually produce a second crop of leaves.
Control can be done with Bordeaux spray. I like to start with the application of a complete fertilizer, such as 12-12-12. This will improve the vigor of trees weakened by repeated attacks of anthracnose.
Some species are less affected.
London planetree is much less susceptible than American sycamore; oaks in the red oak group are generally more resistant than white oaks.
If you take some of the affected leaves to your local County Extension Office, they should be able to identify the problem and offer suggestions for treatment.
Hoping Bryant Redhawk is still watching this thread...
American persimmons, all looking like this. I'm in S MO, we have gotten some hellaciously wet weather, alternating with very dry. These trees (one adult tree, about 200 seedlings, look about 3 years old) are down in my lower pasture, where they DO get really soggy when it rains a lot. I'm guessing Anthracnose? If so, is this a problem knowing I am planning to put a lot of fruit and nut trees within 50 feet or so of them, out of the soggy zone? And if so, any suggestions? I was totally thrilled when I realized all those seedlings were persimmon, I hope they aren't a problem....
Thank you for any help
hau Pearl, Yes that is Anthracnose, but don't worry too much, all my persimmons have it here in Arkansas and they still put out good amounts of fruit every year.
The way to help control this disease is to rake up all the leaves and burn them in a covered barrel so no spores can escape the heat of the fire.
I have a barrel with a drilled lid just for doing this sort of disposal, I used a 1/4" bit and drilled 18 holes in the lid, it is enough air flow and still keeps everything inside the barrel.
This really shouldn't be a huge problem, and it will vary year to year since it is dependent upon wet conditions (our humidity allows it to hang around regardless of my efforts to get rid of it).
About the best thing you could do to alleviate the problem would be to put in some sort of drainage in that area, this is usually not feasible for most of us.
Thank you sir!
Only problem with "improving drainage" in that area is the land form in that area makes it the best place on the property to make a pond, it's already half ponded naturally. It's down close to a creek, where it is always foggy in the mornings, and my property and the neighbors drain through there.
I'll try doing something about the leaves in the fall, the reason I'm guessing the age of the seedlings at 3 years is the neighbors say it's been that long since the place was cut, the grass is over my head. Not sure I can FIND the leaves and I doubt I'll be able to get the brush cutter down that far this year.
Maybe I can move a few of the seedlings up slope.
I'll see what I can do, now that I know what it is. Do you think the other trees I plan to put in, not in the pond area, but higher up, will catch it? Whatever fruit and nut trees I can get cheap or propagate that will grow well. It's a north facing slope, so I have some really interesting microclimates, including all that fog down there. It's water harvest heaven down there, and I'll be running earth tubes to the house from there to cool it too.
I appreciate your wisdom, as always! There are some people in the world I wish I could run a cable to their heads and download all the stuff they know, you are on that list
you might want to look into something like cranberries for that marshy area or Sassafras trees, they can take the water quite well.
The foggy mornings would be good for those too.
Or, you could go with a pond and raise some fish for the table.
If you are putting in other fruit trees just put them up hill from the persimmons and they should be fine.
Trees are more resilient than they are usually thought of being. I've seen trees hit by fire blight for years keep on putting out new growth.
One of the things I've noticed on my land is that most of my issues go away once I get the "cedars" cut down (actually a type of Juniper but these are sacred to my people so I don't remove them unless I have to.
The Japanese rice sickle does a great job of cutting grasses like that, in an area that soggy you will want to be pretty observant, there are some vipers (copper heads and Water Moccasin/Cotton Mouth) that love that sort of environment
Bryant Redhawk: Update and related question
The persimmons still show the spots. I did finally manage to get all the way down there mowing, and knocked down the heavy grass. They all lost their leaves this last summer in high heat/drought so no leaves to clean up this year.
I was give some chestnuts and hickory to grow, would they be ok right next to the infected persimmons? I'm looking for deep dirt and out of the way, wondering if that's a viable location. Otherwise, they need to be in a nursery bed until I can move them to a spot after it's been dirtworked, and trees never seem happy if you transplant them.
Thank you :D
Edit: the cedars are my main north windbreak, someone planted them nicely, spaced well, they are well grown, I don't want to cut 200 trees...
Now that I think on it, I'm not sure they are on my side of the fence. The fence is deep inside the tree line, I'd have to dig to find it.