The oil residue may have fried your leaves. Once a week is too often. Spray your leaves every three days with a stiff stream of water and make sure the soil around your tree is moist. I recommend using AzaMax from General Hydroponics. But if you love that tree, best to have it inspected by a certified arborist and let him treat it. Good Luck, Nancy
Japanese Maple Tree Branches Dying After Heavy Use Of Neem And Volck Oil
Question From: J. Walsh - OHIO
Q: Hi Nancy, I have a huge spider mite problem! I have used Neem oil, and Volck oil on my Osakazuki Japanese Maple and it doesn't seem to do anything. I have applied it once a week for 3 weeks and the tree looks like it's doing better, then I see branches starting to die! Do you have a suggestion of what my next step should be? Please help!