Question
Hello David,  I have two white birch trees which are approx 4 years old and stand 9-10 tall.  This spring they came out with great foliage and developed the tassels(seeds), now they are loosing a inordinate amount of their leaves. past years I recalled they loose some and other in the neighborhood did too, but this year mine have really taken for worse.  I don't see bugs and treated base of trees with Baeyer Advance tree protection 1x/year. The leaves get a lot of dark pin-size blotches on them, then turn yellow and fall off.   I suspect  a disease of some kind, but not know where to get more information on what to do.  I would like to save these trees.   I live near a forested area which seems always bring pests to the yard and ornamentals.  This year I treated lawn with grub killer since the moles were bad last year.   Appreciate any advise on identifying potential source of problem and what to do.  The trees are in full sun so am certain summer heat along with a disease or pest will kill them this summer if not addressed soon.  thank you very much for any help. Dave, Clayton, NC

Answer
The insecticide should take care of any bug issues.  The tree may have one of many fungal diseases that affect birch trees.  If possible, try spraying the tree with Daconil fungicide.  Treat once and then re-treat in about 10 days.  See if this will abate the leaf defoliation.  Good Luck.