How Often Can You Put Neem Oil On Vegetables?

Neem oil includes at least five recognized insecticidal compounds in its pure form, the most important of which is Azadirachtin.

The Azadirachtin is then removed from raw neem, and the clarified hydrophobic neem oil that results becomes a contact poison, blocking the airways of any insects that come into touch with it.

This makes it effective against a variety of fungi, including sooty mold, and it can even assist your plants resist root rot to some extent.

Neem Oil Toxicity

Despite the fact that neem oil is generally harmless and is utilized in a variety of healthcare items, some people remain concerned.

  • You or a family member is expecting or breastfeeding a child (Neem soil soaks and cakes)

In little children, azadirachtin has been known to produce seizures and other serious side effects. There is some evidence that it can cause miscarriage or other pregnancy issues.

Honey, like many other natural compounds, carries similar hazards throughout pregnancy and infancy, so be cautious, not alarmed.

Neem oil does not harm bees, ladybugs, or other beneficial insects when used properly.

However, any sprays should be applied at twilight or morning to prevent injuring these garden pals.

Always remember that neem oil is non-discriminatory, but it also evaporates quickly when applied topically, so timing is crucial.

Neem Oil Foliar Spray

Simply add 1 teaspoon of Dawn dish soap or pure castile soap per gallon of water to emulsify the water.

After that, add 2 teaspoons of clarified hydrophobic neem oil to a spray bottle or a garden sprayer.

Spray the entire plant, paying special attention to the undersides of leaves and any crevasses.

Harvest your crop after waiting at least one full day following the last treatment and properly washing it.

This will not only ensure that there is no liquid neem stuck in the crevasse, but it will also remove any soap residue.

While foliar sprays are the safest alternative, they do take more time and work than other options.

What Concentration Should I Use?

Clarified neem is available in a variety of concentrations, ranging from.5% to 3%.

The various numbers show how much Azadirachtin is left, and each concentration excels at distinct tasks:

  • The most common dosage used for preventive and mild infestations is 1% percent.
  • For heavy infestations where the 1% percent isn’t strong enough, the 2% percent is employed.

Although there are additional percentages, these are the ones you’ll utilize the most.

Neem Oil Soil Soaks

Neem soil soaks, the polar opposite of foliar sprays, are the simplest to use yet the most effective.

A soil soak is created in the same way as foliar sprays, with the exception of two tablespoons of 100% cold-pressed raw neem oil per gallon.

Pour 2 to 4 cups of the mix straight onto the soil surrounding the plant’s roots on a day when you would typically water the plant, being careful not to splash the plant itself.

In the soil, neem can persist anywhere from 3 to 22 days, however the majority of it is absorbed by the plant roots.

After being absorbed, neem becomes a systemic insecticide that can last up to 22 days in the plant.

Only pests that gnaw or penetrate the plant will be exposed since it mixes with the sap.

There is no proof that this method contains neem in fruits like tomatoes or other berries or vegetables, but it is better to err on the side of caution if needed.

Neem Cakes

Neem cakes are the materials left behind from the production of neem oil, and they are perhaps the most underrated variety of neem.

Only trace amounts of oil are present in the cakes, which are employed as a fertilizer with an NPK of 4-1-2.

Follow any product directions, and keep in mind that neem cakes are only effective against ground-based pests like grubs.

Because the cake contains very little neem oil, it should not pose a risk to infants.

However, there is no solid evidence that any neem makes its way into the produce from neem cakes, so proceed with caution.

How Often To Use Neem Foliar Sprays

Clarified hydrophobic neem oil, a processed form of organic neem oil pesticide, is used in neem foliar sprays.

The majority of the active components in Azadirachtin have been eliminated, resulting in quantities of.5% to 3%.

Neem foliar sprays choke insects on contact and kill some external fungal illnesses and infections as a topical remedy.

However, for it to function, it must be applied every other day for at least 14 days.

To avoid contact with helpful insects like ladybugs and honeybees, apply at night or morning.

After you’ve gotten rid of any existing infestations, you can use the foliar spray once every two weeks as a preventative measure. When using Neem Oil Sprays, be sure to read the Do’s and Don’ts.

How Often To Use Neem Soil Soaks

Pour this neem oil for plants on the soil and allow the roots to absorb it, converting it to a systemic pesticide.

The Azadirachtin will last for up to 22 days inside the plant. Only piercing or chewing bugs will be affected.

Repeat the soil soaks every 21 days to maintain the effectiveness of the Azadirachtin.

Most infestations are killed by azadirachtin without hurting pollinators or useful creatures like earthworms or predator species. It will, however, aid in the treatment of a variety of bacterial and fungal illnesses, including some types of root rot.

When NOT To Use Neem Oil

While neem is non-toxic and is commonly used in toothpaste, it is generally acknowledged that you should not apply it to a food plant on the day it is harvested.

You can use a foliar spray the day before harvest or soil soaks. If you don’t apply it on the day of harvest, you’ll consume less.

Another important requirement is to test a small portion of a plant one day prior to utilizing neem oil goods.

Even natural materials can cause allergies and sensitivities in plants, just as they can in humans.

You can check for evidence of chemical burns or allergic responses by testing a small section of the plant first.

You may only need to test once if you use neem on a regular basis. However, if you haven’t applied neem oil on the plant for a long time, you should always retest it.

You should stop using neem products on that plant right once if you see an adverse reaction during testing or regular use.

Is it OK to eat veggies that have been treated with neem oil?

Neem oil is generally considered safe for application on edible plants, such as vegetables. It’s a fantastic organic pesticide that’s also a fertilizer and is environmentally benign. It’s also used in a variety of other industries. It’s ideal if you handled it with caution because it can cause skin irritations, allergic responses, and serious health problems if consumed. When handling it, wear gloves and properly wash the edible plants before eating them.

Is it possible to take too much neem oil?

Researchers have discovered that neem oil includes dozens of different chemical components, but azadirachtin is by far the most important.

This naturally occurring substance does not kill pests right once, but once consumed, it interferes with their ability to feed, molt, and reproduce, causing them to die within a week.

Neem oil coats insects with a thin layer of oil as well. Adult, hard-bodied bugs like leaf-footed bugs, squash bugs, and stink bugs will be irritated but not killed if sprayed with neem oil. Aphids and spider mites, for example, are more vulnerable to anything that coats them in an oily substance, especially if they’re in their nymph stage. The azadirachtin will kill them if the oil doesn’t.

Thankfully, the oil won’t harm helpful pollinators, and once it’s diluted, sprayed on plants, and exposed to sunshine and the environment, it will begin to degrade swiftly.

There are several things you can do to make your neem oil more effective, but in general, you shouldn’t use it more than once every 4-7 days.

In other words, if you use neem oil every 1, 2, or 3 days, you’re overdoing it and risk causing long-term damage to your plants.

This is because neem oil coats the leaves, branches, and flowers of your plants in a thin layer of oil.

As I mentioned above, this oily layer will begin to break down after a few hours, but if you keep reapplying neem oil without properly timing or spacing your treatments so that the oil breaks down completely in between, you risk damaging your plant in two ways.

Foliage Burns

This is the most evident way that neem oil might harm your plants. Simply explained, neem oil is an oil, and it will heat up if exposed to direct sunshine before entirely drying, just like the oil in your frying pan does when exposed to higher temperatures.

When neem oil heats up, it will likely burn any foliage it comes into contact with, generating streaks, splotches, or even spots, as well as eventual leaf death. If you coat too much of your plant with neem oil, you risk killing it completely by damaging too much of its foliage.

Applying neem oil sprays in the early evening is the easiest method to avoid these issues. When the sun is sinking but the light is still bright enough to see clearly, I do so. This ensures that the neem oil has at least 10 hours to dry before the sun rises the next day.

I once forgot to apply neem oil in the evening and, against my better judgment, opted to do so first thing the next morning. I figured that by starting early, I’d avoid getting burned and that it would dry before the sun could do any damage.

Thankfully, I had only used a small amount of neem oil on a few plants, so they recovered quickly. But the incident taught me a valuable lesson: if you skip a neem oil treatment in the early evening, don’t try to make it up the next morning. Simply wait until the right time the next day to spray your plants.

Aside from the risk of foliage burns, regular neem oil applications might have unforeseen consequences on three key biological processes that all plants go through:


Photosynthesis is commonly understood as the process by which plants convert carbon dioxide, sunshine, and water into oxygen and carbohydrates, but how this happens is less well understood.

Simply put, stomata (or stoma if referring to a single pore) are epidermal pores found in plants. By absorbing carbon dioxide from the atmosphere, these small apertures serve an important role in photosynthesis. Cells that serve as gatekeepers surround each stoma. If the plant has enough carbon dioxide, the cells close the stoma to reduce or stop the flow momentarily; if the plant has insufficient carbon dioxide, the cells open the stoma to allow more CO2 in.

As a result, stomata are essential for photosynthesis. They control how much and how often carbon dioxide comes into the plant, so regulating one of photosynthesis’ major components, but not playing a role in the actual chemical processes taking place inside the plant.


Stomata open in order to draw in carbon dioxide, but they also leak water in the process. There’s a lot of it. An acre of maize can transpire up to 4,000 gallons of water per year, whereas a single huge oak tree can transpire up to 40,000 gallons, according to the US Geological Survey.

Heat, humidity, wind speeds, and soil moisture, to mention a few, all influence plant transpiration, but it’s a crucial aspect of the plant’s life cycle, and the stomata regulate when and how much each plant transpires at any particular time.

Oxygen Release

When plants engage in photosynthesis, they collect carbon dioxide from the atmosphere and combine it with water to produce carbohydrates and oxygen using energy received from sunlight. The excess oxygen is subsequently expelled as an unwanted consequence of the photosynthetic activity.

These exchanges, not surprisingly, also take place through the plant’s stomatal openings, especially during daylight hours. As a result, the open stomata serve a dual purpose: they allow CO2 in while also enabling oxygen to escape.

Anything that interrupts these stomatal pathways, as studies have demonstrated, has a negative influence on plants, slowing their biological processes and stunting their growth.

And here is why I’m afraid of neem oil: if you spray too much and too often, you risk coating and re-coating your plant’s leaves in oil, which can block the stomata, making it difficult for the plant to take in carbon dioxide and expel both water and oxygen.

Is it possible to overuse neem oil on plants?

Yes, too much neem oil can harm plants by forming a coating on the leaves’ surface. The leaves are suffocated and unable to produce food as a result.

Due of the heat from the sun, the excess neem oil will cause the leaves to burn. If you spray it on the ground, the neem may penetrate the roots and cause damage.

If you use too much neem, it might be poisonous to your plants and cause difficulties. Beneficial insects and aquatic life can potentially be poisoned by it.

Neem oil is also safe to use on edible plants. However, you must take the same measures. You must dilute it with water and apply the appropriate amount. Plants will be harmed if they are exposed to too much neem oil.

When it comes to neem oil, how long does it last on plants?

Neem oil has a half-life of 1-2.5 days after being applied on your garden plants, according to the National Pesticide Information Center.

This means that every 24-60 hours, the strength of the neem oil solution drops by 50%. In other words, neem oil is 50% less effective after 1-2.5 days on your plants than it was when it was originally sprayed. It’s just 25% effective after two to five days. And it’s likely lost most, if not all, of its early efficacy after 4-10 days.

This is why, if you have an insect infestation in your garden, you should reapply neem oil every 4-7 days.

Neem oil is a wonderful natural substance, but it degrades quickly, and in my experience, one application rarely suffices to fix whatever pest problem you’re dealing with.

Benefits of Neem Oil on Tomatoes

It has a well-deserved reputation for eliminating a wide range of dangerous insect species.

As a result, you can treat your tomatoes up to 24 hours before harvesting without risk.

It will attack infestations and disperse before any helpful insects arrive if applied topically at dusk or dawn.

What plants should be avoided when using neem oil?

So, Neem Oil is a very efficient pesticide, but can it be used on any plant? You can use Neem Oil on almost any plant, but it won’t work on plants that don’t have smooth surfaces. It won’t work if your plants have fur, needles, or any other way for bugs to crawl deeper into the leaves and avoid the Neem Oil. Plants with fuzzy leaves, such as most Calatheas, should not be treated with Neem Oil.

Is it necessary to wash neem oil off my plants?

In most circumstances, neem oil does not need to be rinsed off of typical indoor plants. However, if you used neem oil to treat your indoor herbs and indoor fruit trees that you are growing in a greenhouse or solarium, it is critical to thoroughly rinse the herbs and fruit before consuming them.

This is because, although being an organic botanical product, neem oil is a pesticide and does contain certain toxins.

In summary, if you’re going to eat herbs or fruit, you should definitely wash the neem oil off. However, if you are not consuming any portion of the house plants, there is no need to do so for typical indoor plants.

Is neem oil sprayed on the soil or the leaves?

  • To prevent the creatures from spreading, isolate the diseased plant from any other houseplants.
  • If the plant is huge, you may need to do this in a bath or shower to completely wet the leaves.
  • Use your ready-to-use neem oil spray to spray the leaves, stems, and soil. (It should contain clarified hydrophobic neem oil, which can instantly capture bugs.)
  • Allow for two to three days of resting. Keep it out of the sun and away from your other plants.
  • Steps 24 should be repeated once or twice more to guarantee that it has completed its task. Return the plant to your greenery collection after two to three days.