Neem oil is practically a necessity for many gardeners and plant enthusiasts. This natural substance is safe for use on most plants and is safe around humans and pets in small to moderate amounts.
However, as with all products, there are times when neem oil isn’t as safe to use as it normally is.
For this reason, you should always consider the rules on neem oil usage before attempting to apply it.
How To Apply Neem Oil
It’s important to know how to properly apply neem oil, as improper use may harm beneficial insects, aquatic life, or even your plants.
Thankfully, the rules are pretty simple and easy to remember.
Where NOT to use Neem OIl
Neem oil is safe for many species, but it doesn’t distinguish between beneficial and harmful insects when used topically on plants.
Its ability to disrupt hormones can also create health risks under certain circumstances.
Here’s a key list of when you should avoid using certain neem products:
- NEVER use foliar sprays during the day, as bees and other beneficial insects and pollinators may contact it. Read Neem Oil and Bees.
- NEVER use neem foliar sprays near a beehive, as the wind may carry droplets to the nest.
- NEVER use neem products near water features that contain aquatic life. Neem is mildly toxic to many fish and amphibian species, so neem products are banned in Canada and the UK.
- AVOID applying when children or pets are around, as they may ingest the neem beyond safe quantities.
- NEVER leave neem products around small children, as it has been known to cause seizures or other side effects when ingested by young children, although these risks dissipate as the child ages.
- AVOID coming in direct contact with neem products if you are pregnant or breastfeeding, as it can cause complications or even miscarriage and may also contaminate your breastmilk.
Testing Plant Tolerance
You should always test your plants before applying neem products.
Some plant species have a natural intolerance.
Meanwhile, plants that should be tolerant of neem may have a sensitivity or allergic reaction, just as humans sometimes do to peanuts or other normally innocuous products.
To test your plant, apply a very small amount to an isolated spot on your plant.
For foliar sprays, apply to a single leaf, while a few drops of soil soak may be added to a plant’s stem near the base using an eyedropper.
Wait for 24 hours, occasionally checking for any negative reaction.
If the plant shows signs of sensitivity, avoid using neem products on that plant.
However, if there’s no reaction, you may go ahead with the treatment.
Some guides suggest testing before every use, while others consider it a one-and-done.
We suggest personal discretion in how often you test, as plants may gain or lose sensitivity over time, but you should try to test at least annually.
When to Apply Neem Oil
As mentioned before, neem oil can harm beneficial insects and bad ones if applied at the wrong time.
To avoid harming bees, ladybugs, and other garden friends, always apply your needed treatments at dawn or dusk.
This is when butterflies, moths, bees, and other bugs are least active.
Neem foliar sprays only take 45 minutes to 1 hour to evaporate, so they’ll be gone by the time these helpers start their daily (or nightly) routine.
This also gives neem soil soaks time to absorb into the ground.
Another reason to apply at these times is to avoid sunburn on indoor or outdoor plants.
Because neem oil is mixed with water, applying when the sun’s up increases the risk that the sunlight will scorch the leaves.
While neem is generally non-toxic, you don’t want to get a mouthful when eating fresh produce.
To avoid this, always apply the neem at least one day before harvesting.
It is also best to apply soil soaks when the plant is thirsty, so you don’t accidentally overwater.
Applying Foliar Sprays
Foliar sprays are more involved than soil soaks and must be applied more frequently.
Spray the entire plant, being sure to get the undersides of every leaf and any crevasses.
During an infestation, you will need to reapply every other day for 14 days.
As a preventative, you will need to do one application every 14 days.
Applying Soil Soaks
Soil soaks are much easier to apply, especially with larger plants.
More on Watering Plants with Neem Oll
Pour 2-4 cups of the mixture (or more, for larger plants such as citrus trees) directly onto the ground around the plant’s base.
Try to avoid splashing the stem, trunk, or any exposed roots, and aim to cover the ground in a radius, so you cover most of the root area.
Neem soaks get absorbed into the plant, so they last a lot longer.
Apply once every 21 days for both infestations and as a preventative.