I would like to know if Neem oil can be used on Japanese maple, gardenia, hydrangea and knockout roses. I have spider mites in my flower and shrub beds and need to know if neem oil is safe on these plants and/or shrubs.
Neem Oil on Plants
Certified GKH Gardening Expert
Yes, Neem oil is safe to use on these plants. Here is more info: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
Neem Oil can be used on the Knock Out roses but it depends on what you are out to control as the Neem Oil may not be the best choice for some insect problems. Be sure to read the label on the type you buy to see if it will control the particular insect. For control of Spidermites you need to use a miticide and not an insecticide. The insecticide will only kill off the natural predators of the spidermites and can lead to a major explosion in the number of spidermites. Here are a couple articles for you to check out: