There are several benefits to using neem oil for plants, but also a few considerations. Neem oil is banned in both the UK and Canada for its active ingredient, Azadirachtin, which has shown slight toxicity in marine life.
However, it is considered one of the safest and most beneficial organic pest control insecticides throughout the world.
You often hear about organic neem oil being used with a wide range of plants, but might not have known you can actually use it on food crops as well.
Among those crops, tomatoes are often the targets of pests, from grasshoppers to aphids, scale, and the tomato hornworm.
Is neem oil safe for use on tomato plants, and if so, how do you use it?
Can You Use Neem Oil On Tomato Plants?
Not only is it safe to apply neem oil to your tomatoes, they absolutely thrive on it!
Here’s everything you need to know about using neem oil on your tomatoes.
Benefits of Neem Oil on Tomatoes
Neem oil suffers typecasting as much as any good actor.
It has a well-earned reputation for killing dozens of different harmful insect species.
But did you know it’s also a fungicide and has antimicrobial properties?
Learn about Using Neem Oil as a Fungicide
Neem can help fight several ailments, such as root rot and powdery mildew.
It also contains fatty acids and a wide range of micronutrients.
Neem cakes are also an excellent fertilizer, with an NPK of 4-1-2.
Neem oil is non-toxic to humans and pets when consumed in small amounts.
As a result, you can safely treat your tomatoes up to 24 hours before harvesting.
When applied topically at dusk or dawn, it will attack infestations and dissipate before any beneficial insects show up.
Using Foliar Neem Oil Spray on Tomatoes
Applied as a foliar spray is a popular treatment method, although they require more frequent application.
To make your own foliar spray, you will need to:
- Emulsify 1 quart of water by adding 1 teaspoon of Dawn dish liquid or pure castile soap and gently mixing.
- Next, add in 1 teaspoon of clarified hydrophobic neem oil and fill a spray bottle.
- Clarified neem oil has the Azadirachtin removed, leaving behind trace amounts of .5 to 3% percent.
- Spray down your plants thoroughly, making sure to get the undersides of leaves and any crevasses.
- Repeat every other day for 14 days or until the infestation is gone.
Details on Mixing Neem Oil Concentrate for Plants
You can also apply once every 14 days as a preventative.
Note that foliar sprays work differently than other neem methods.
The spray clogs the airways of the garden pest it comes in contact with, suffocating them.
Within 45 minutes to an hour, the organic neem oil solution dissipates, leaving behind no residue.
Using Neem Soil Soaks on Tomatoes
Neem soil soaks are perhaps the most effective use of neem oil, but it takes longer for the effects to show.
To make a neem soil drench, add 1 teaspoon of 100% percent cold-pressed raw neem oil to a quart of emulsified water.
Pour 2 to 3 cups of this mixture around the base of the plant and allow it to soak into the soil once every two weeks during an infestation or once every three weeks as a preventative.
Your tomato plant will absorb the neem through its roots, turning it into a systemic insecticide.
The oil remains in your plant for up to 22 days, targeting piercing insects and infections.
In this form, the oil mimics an insect’s natural hormones, causing them to stop eating.
It can also interrupt progression to the next growth stage in nymphs and cause infertility in adults.
The process is slower than with foliar sprays, but can be far more effective over time.
Related: Does Neem Kill Tomato Hornworms?
Using Neem Cake on Tomatoes
Neem cakes are the solids left over from extracting neem oil.
They’re commonly crumbled up and used as fertilizer due to the high content of micronutrients and 4-1-2 NPK rating.
Simply follow the instructions on the package to apply this form of neem to your tomato plant.
Neem cakes are excellent protection against grubs and nematodes and can help fight off root rot and other subterranean infections.
Additionally, the cakes provide excellent nutrition for your tomato plant, which can improve flavor.
While neem cakes contain trace amounts of Azadirachtin, the amount that gets absorbed as a
is far lower than neem soil soaks due to the low amount of oil in the cake.