Aphids or hoppers are my curling problem. Spraying pesticide takes care of them.

Mykl, I'm sure there are some aphids and leaf hoppers because the tree is situated next to a vast area of mostly native vegetation, and I never spray pesticides. However, I don't ever find any when I examine the foliage closely. With virtually all the leaves curled, wouldn't you expect to see quite a few of the critters whenever you decide to look?

Axel's water theory is plausible, except with so much late season moisture in my area this year, everything else (including all of the native vegetation) is continuing to show strong new growth without any supplemental irrigation. It might be that the tree happens to be in a spot that drains particular fast, and where the subsoil holds alot less water than the other soil in the area. When you see the curling, water stress is what naturally comes to mind, but all of the other normal signs of water stress are missing. I grow wine grapes commercially, so I have some experience with water stress, particularly with vinifera. Perhaps there is some interplay going on with soil chemistry and soil moisture, rather than exclusively soil moisture.

I'll keep treating the tree with Neem Oil to counteract the apple scab and possible powdery mildew and critters. I'll make sure it gets plenty of water too. If the leaves don't relax after that, I'll test the subsoil Ph and send a subsoil sample off to the lab to check other aspects of soil chemistry. Maybe the curled leaves are the tree's way of telling me that something in the soil chemistry is way out of whack.

I have a 3rd leaf Jonagold that did the same thing last year which was dry but I irrigated and figured I messed up on not enough water. There are other 3rd leaf varieties on 3 sides of the tree and they never showed the upward curling last year. This year has been WET so I now know the curling this year is not a moisture issue and the tree has no disease problems; however, leafhoppers were present this year and last on all the trees and I have been too lazy to spray for them and have no other insect problems to date. Maybe Jonagold just likes to curl when the hoppers are infesting it, beats me, the other trees are just fine.

Michael, I agree, its not related to how much water the trees are getting. This year, none of the plants in my garden have experienced any water stress yet.

Also, of the three apple trees (all near each other), the Jonagold has the upward curling condition far worse. If it's leafhoppers though, they are doing their dirty work without leaving a trace. I can't see anything wrong with most of the curled leaves, except that they want to curl rather significantly. I don't know if it's a clue of any sort, but the leaves on the newest growth on the tree curl the worst. The leaves toward the base of most branches almost look normal. Go figure . . .

I see the same curling on my Jonagolds. The trees are over 10 years old and on 111 rootstock. I've seen this several years on the trees, but they always produce excellent apples.

I just came back from the local nursery. I have an apple tree ( Rising Sun Fuji) that all the leaves have curled. Their explanation was that the tree has TOO MUCH WATER not that it was or had been too dry. There is no leaf damage at all. All green and no issue on any of the leaves except for the Japanese beetle damage that just started this last week.

Too much water, not enough water. This sounds a little sketchy to me. The leaves on my Jonagold are also curling up. Looks to me like with all the different locations reporting the same thing this might be a normal occurrence for Jonagold. I sure hope so. Jonagold apple is high on my like list. What say you?

According to Warren Marnhart in "Apples for the 21st Century", Jonagold prefers a cool, rainy mild climate like the PNW or England/Holland, while Gala prefers a dry hot climate like Eastern Washington. Could be a reaction to the climate.
John S
PDX OR

I just planted 104 trees (Apples, Pears, Peaches and Plums) and 48 Blueberry Bushes this spring in Eastern NC. I had a small percentage of trees that did not make it the first 3 Months, but I have the same curling leaf issue with all my Jonagolds. I also see it to a lesser degree on my Fuji and Goldrush. The other apple trees (Pristine, Mollie Delicious, Gala, & Honeycrisp) all look great. I am new at this so I am not good at providing advise but just wanted to pass on that I am seeing the same issue and after reading all the post I am thinking Jonagold may not be a good choice for Eastern NC. Too hot and humid. I will watch and see.

I have the same problem and this weekend I talked to a guy at "Verde Valley growers" They grow wholesale and to the public. This is what he said it is caused by thrips in this area. Arizona does have Chilean thrips and I do have them in my yard. Some of their trees looked just like mine. I kept thinking for the last 10 years it was a water issue. I do spray, but if you know anything about thrips you know its pretty done hard to kept them away from plants. My three is a golden delicious.

Looking at the leaves I do not see and insects. I understand the thrips are small but you can see them with the naked eye. I see not real insect problem. And again, it is not affecting my other trees. At least not yet!

Thrips blow in the wind they can be on one plant and within a few hours move on to something else, they also swarm. They like light colored blooms and new growth. They could of been on the tree when it leafed and now moved on. They also love roses, grapes, Satsuma plums and privets(my issues). I have 2 apples w/n 15' of ea. other, one has the issue the other has none. Check your plants using a white sheet of paper and give the branches/bushes etc. a good shake see what drops. Give me White fly, Aphids even gophers I'd take them any day compared to thrips. Arizona