Anthracnose starts as dead leaf areas between leaf veins, or on the tips of leaves. When severe enough, leaves will fall. The good news is that it rarely harms trees. If enough leaves drop, a new set comes out in 4-6 weeks and we start all over. The next set of leaves may also get the disease, but they may not. Treatments when you see the symptoms of this disease are simply wasted time and money.

Apple scab is a similar disease that can cause premature leaf drop in apples and crabapples. The same scenario applies here. If you are on a regular spray schedule for fruit trees, it should prevent most of the problems. You could also spray crabapples this way, but you would have to weigh the cost and benefit since no fruit production is involved.

Plum pockets is caused by a fungus on trees in the stone fruit family. This would include mainly peaches and plums. It is rather striking with the bright red swellings on the green leaves. This disease can only be prevented with a dormant time application of a fungicide on your trees. Seeing it now means that you probably should have sprayed before the buds began to swell (meaning before leaves actually came out).

What's the end result? Trees get leaf diseases each year. Very rarely are any trees killed by these problems, and those that die are usually one foot in the grave to begin with. The only things that help the trees at this point is fertilizing moderately and watering during extended dry spells (which might be a while!). The fertilizer helps trees cope with some of the lost energy from lost leaves and the effort to put out a new set.