How Often Can I Spray Neem Oil On My Plants?

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 okay if I sprinkle neem oil on my plants on a daily basis?

Because Neem Oil takes a few days to take effect, keep washing and spraying your plants for a few days. If your plants aren’t currently being bothered by bugs and you’re using Neem Oil for pest control, you can spray them once a week to keep them safe from pests and infestations. If you clean out your plants on a regular basis, this is a good time to spray them with your Neem Oil combination before wiping them off. Your plant will not only look fantastic, but it will also be protected from any pests that may wish to reside in or around it.

Thank you for taking the time to read this article. I hope it proves useful in maintaining the health and beauty of your plants! If you need additional information on a certain plant, you can always request a plant guide or contribute a plant to acquire one for the plant you’re having difficulties with.

Is it possible to give a plant too much neem oil?

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.

How long does neem oil keep plants alive?

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.

Is there such a thing as 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 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 it okay to water my plants after using neem oil?

The nasty fungus gnat, oh no!! These tiny, fly-like parasites prefer to lay their eggs in the damp soil of indoor plants, where the larvae can feed on the plant’s roots.

Because of their lifecycle as both a flying insect and a soil larvae, fungus gnats can be difficult to eradicate. It’s also a good idea to treat all of your plants at the same time.

In combination with yellow sticky traps that can catch adult gnats, I like to use neem oil as a soil drench. Watering your plant with a diluted neem oil solution will help rid the soil of the larvae while causing no harm to the plant.

Remember that gnats are drawn to damp soil, so only water your plants again until the top 1-2 inches of soil are dry to help tackle the problem.

Is neem oil harmful to leaves?

Neem is a pesticide that is produced naturally from the seeds of the neem tree (Azadirachta indica). Tropical woods in Burma, India, and Sri Lanka are home to neem trees. For hundreds of years, the tree’s natural range has been employed as a botanical insecticide. Neem products have become fairly easy to purchase at most garden centers, thanks to a growing interest in organic and less-toxic pesticide solutions. Many gardeners may now reach for it first when they have a pest problem. If you understand how neem works and simply apply items according to label instructions, it can be a valuable component in an integrated pest management strategy.

One of two active components is commonly found in neem products. Azadirachtin, a chemical obtained from neem seed oil, is primarily responsible for insect killing and repellence. The residual material is known as clarified hydrophobic neem oil after the Azadirachtin is extracted from neem oil. Azadiractin is exclusively found in commercial insecticides and is used to alter the hormones that control insect growth and reproduction. The active ingredient in ready-to-use neem oil sprays that may be purchased at a garden center is clarified hydrophobic neem oil.

Neem oil can be used to treat a variety of insect and fungal diseases. It suffocates insects by coating their bodies in oil, which clogs their breathing holes. It works best on insects that are still juvenile. Adult insects aren’t usually killed when they reach maturity, so they can continue to feed and reproduce. As a result, timing a neem oil spray requires constant monitoring of insect lifecycles.

Even if you apply neem to immature-stage insects, don’t expect to see results right away. It takes time to work, and it may be necessary to reapply to totally control bug populations. Pests handled by neem pesticide products include aphids, beetle larvae, caterpillars, lacebugs, leaf hoppers, leafminers, mealy bugs, thrips, and whiteflies. Make sure to identify insects precisely, and only use neem oil if the pest is indicated on the label. Both beneficial and pest insects can be harmed by neem.

Powdery mildew is one of the fungal diseases that can be treated with neem oil. It acts by preventing fungus spores from germinating and penetrating leaf tissue. Although neem won’t “cure” a plant sick with a fungal disease, it can assist limit the illness’s spread to good tissue.

Products containing neem oil are frequently labeled for a variety of crops, including herbs, vegetables, fruits, nuts, and decorative plants. Neem oil can harm plants by burning their foliage, regardless of the type of plant being treated. Use with caution on newly transplanted or stressed plants. Though neem oil must thoroughly coat plants to be effective, it is a good idea to try the product on a small area first. If there are no toxicity signs in that area, the entire plant can be treated.

This article’s use of specific brand or trade names is only for educational reasons. The University of New Hampshire does not recommend one product over another of identical composition, nor does it guarantee its efficacy or quality. The user is responsible for only using pesticides according to the label’s instructions and in accordance with the law. Product availability is subject to vary based on the state of New Hampshire’s registration status and other considerations.

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.

Is it possible to spray neem oil on the ground?

Why is Neem Oil chosen over other insecticides and insect repellents in the garden? Neem oil is non-toxic and safe to use for the environment, humans, pets, and even plants and soil.

How often should you use neem oil?

Some plants may be killed by neem oil, especially if they are young and the oil is applied too heavily. Before applying it all over, test a tiny part of the plant and wait 24 hours. To avoid leaf burning, use neem in the evening to outdoor plants and out of direct sunlight to interior plants. All surfaces of the leaves, including the undersides, should be sprayed. As needed, reapply every seven to fourteen days.