Q.SPRAYING OYSTERSHELL WHEN TEMPERATURES GO BELOW FREEZING AT NIGHT
Our cotoneasters look as if they could burst into leaf very soon. However, at night the temperature is falling 3 or 4 degrees below freezing. Should I treat against oystershell now? Or would it be advisable to wait until there is no risk of frost at night? I look forward to hearing from you. Thank you very much.
Certified GKH Gardening Expert
You can apply horticultural oil before bud break in spring to suppress any existing scale. The temperature shouldn't make a difference.