UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

Monthly Tip

Neem Oil

Tip description

Photo credit: Karen Schaffer
Neem products are derived from the neem tree, Azadirachta indica. But most neem products on the market lack the active insecticidal ingredient azadirachtin. Neem oil, called “clarified hydrophobic extract of neem”, is still effective as horticultural oil for smothering juvenile insects and may be effective in suppressing powdery mildew. But it won’t be effective in cases where azadirachtin is required. Like any horticultural oil, neem oil can potentially damage plants by burning their foliage and should be sprayed at dawn or dusk to protect bees and other pollinators. When using any pesticide, it’s important to reach an accurate diagnosis first and understand that no product helps solve every plant problem. Neem is not a cure-all.

More information: More about Neem

Months applicable
  • Any month
  • 3. Pests and Diseases

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