I live in Arlington Heights and I have two apple trees that I would estimate to be over 30 years old. They get pretty much full sun all day long. They are also near a low area of my yard which floods for a couple weeks each spring. AThe trunks are out of the water, but they stand right next to the standing water.

When I bought the property 8 years ago, the trees were very overgrown, and every year, I've alternated between trimming them back, and then thinning their branches. They have always had yellow spots on the leaves with a brown spot in the center. The fruit has always had dimples and brown spots on them, but have been getting worse. This year, one of the trees has had very little fruit on it except for one branch that has a normal amount of fruit. When you look at the tree, it looks generally yellow, because of all the spots.

Last year, I started spraying the trees with horticultural oil (the petroleum based oil) before the blossoms occurred, and while it seemed to help early in the season, the spots developed in mid summer and are as bad as they have ever been. I don't know what kind of apple it is. It's a small round fruit, like a mackintosh, and a little bit sour, but not like a granny smith. I won't be selling the apples, but I use them for cider and for applesauce, cutting out the bad parts of the apples.

I am hesitant about using pesticides, especially the ones that are applied to the ground and get absorbed into the roots, because I'd like these to be as natural as possible, and I don't want to take the chance of contributing to the dwindling bee population. I don't know if it plays that much of an effect (despite what the internet says) but why take the chance if the spots don't matter that much to the fruit?

My main concern is that this seems to be affecting the fruiting of the trees. It may be that the trees are too old and at the useful end of their life. I have planted a honeycrisp so that if and when I pull out these trees, I have others to take their place, but I've noticed some brown spots on the new tree as well, although not nearly as severe.

I can provide photos, but I don't know how to upload them.

Dear David, Your description of the leaves matches a foliar disease call Cedar Apple Rust. Another common disease that is also likely on your apple trees is Apple Scab. Both are spread in the early cool wet weather by wind, later showing up as the spots you see. Older varieties of fruit trees are more susceptable t diseases than newer ones. Consider using a multipurpose fruit tree sopray to prevent the diseases and insects from damaging your tree. Dormant Oil is effective against overwintering insect eggs and adults. The dimples may be caused by an insect laying eggs just under the skin. That location stops growing and the surrounding cells continue to develop, leaving a dimple. The dormant oil would not have prevented this. Apples trees should be pruned annually. Apples can get into a cycle of every other year bearing if pruned heavy. The tree response is to grow lots of foliage with limited flower production. Your goal of pruning is to balance vegetative growth with flower production so you get a crop of apples every year with moderate vegetative growth. Lastly, all the spots on the fruit will not make a difference if you are making cider and pies. Sincerely, Richard