Leaf Tiers on Annabelle Hydrangeas

Asked August 10, 2019, 12:35 PM EDT

Each spring I remove by hand about 150 tied leaves from my hydrangeas and keep thinking one of these years the leaf tiers will be gone but they come back every year. I have read about using bacillus thuringiensis (BT) as an effective control. If you agree with this treatment plan when would BT be applied (and how) and also is BT available at most garden centers? Thanks, Lynn Balog

Wayne County Michigan trees and shrubs insect issues

1 Response

The nests of the hydrangea leaf-tier are unlikely to cause long term damage to your hydrangeas, although they are unsightly and may cause particulars flower buds to abort. Snipping the affected leaves can remove the leaf-tiers if they are concentrated on a particular area of the plant. Bt or Bacillus thuringiensis, is a treatment option that specifically targets caterpillars and is particularly effective when the caterpillars have recently hatched from eggs. BT should be found in your local garden center. If you use it, be sure to read the label, which will provide instruction about how to apply and whether it needs to be mixed with water.