Is Neem Oil Safe to Use on Cannabis Plants?

The main concerns for most cannabis growers are how to protect their crops from pests and which natural pesticides work to get rid of them. One of the most popular products to use is neem oil, which is derived from the Azadirachta indica tree. It’s yellow or brown in color and has a bitter taste with the smell of garlic or sulfur. It also contains an active ingredient called Azadirachtin that reduces insect feeding.

But is it really safe to use neem oil on cannabis, and what are the best eco-friendly alternatives for growers? In our guide, we’ve provided valuable information about neem oil, common cannabis pests, and one alternative that is just as safe and effective for your cannabis crops. 

How is Neem Oil Made?

Photo credit: queencreektropicals.com

It’s always best to know how natural pesticides are made to see if there are any additives in the product that could affect the growth of your cannabis. Several steps go into making neem oil, such as the following:

1. Seeds are harvested from mature neem trees.
2. These seeds are broken open to separate the kernels. 
3. The kernels are pressed using high-pressure industrial machinery. 
4. This oil is then bottled and sometimes mixed with emulsifiers so it can be mixed with water.

The way neem oil is extracted can affect the quality and composition of the oil. Other manufacturers may use a solvent extraction method using hexane. This solvent is mixed with the neem seeds after the woven drying process. The oil is then collected by vaporizing the solvent. However, there are many problems with hexane that have been linked to respiratory problems and dermatitis, so the solvent levels have to be low to prevent unwanted side effects. 

Is Neem Oil Safe To Use On Cannabis Plants?

The use of neem oil can be safe for cannabis plants as it is a natural product that doesn’t affect the health of your crops, but there are some downsides to the product. In this section, we take a look at some of the concerns of neem oil, especially when used on medicinal-based crops like cannabis. 

Avoid Using Neem Oil On Buds

You can’t use neem oil throughout the growing process. Professional cannabis growers recommend not using neem oil during the flowering stage or on the buds, as it can affect the final taste or smell of your crops. You shouldn’t use anything oil-based on flowering plants, especially those that will be inhaled, as it can cause lipid pneumonia. 

Don’t Expose Cannabis to Heat or Light After Use

If you’re going to use neem oil on cannabis, you should apply it after the sun goes down. Any form of oil-based products can cause glares on leaf surfaces. As a result, the surface temperatures on the leaves become too high and cause burns. 

Unfortunately, pest infestations occur more often when the temperatures are higher, so many new growers make the mistake of applying the neem oil during the day. 

Leaves Behind a Thick Coating

Since neem oil is an oil-based product, when you spray it on marijuana plants, it leaves behind a thick coating, so it can be difficult to remove. Oil may also cause other types of problems when it’s applied too much, like suffocation, which can put crops under a lot of stress and stunt their growth.   

Other Problems with Neem Oil Growers Face

One of the most common problems with neem oil products is the smell and the taste. Some growers mention that these products have a foul smell and terrible taste, which is why they affect the aroma of cannabis buds. Additionally, this smell and flavor don’t dissipate even after rain. Removing any form of oil from cannabis is extremely difficult, so it will affect the quality of your yield. 

What to Do If You Spray Neem Oil at the Wrong Time

Just like any form of insecticide, there is a specific way you must use neem oil. Since this oil is a natural insecticide that cannabis growers use, you may think you can apply the product at any time. But the truth is, if you apply neem oil spray incorrectly, it can kill off your crops. Neem oil can’t be applied throughout the growing stage.

If neem oil was applied at the wrong stage, like during flowering, patience and proper care can help fix it. 

The oil’s half-life on plant surfaces is around two days, meaning it can naturally break down over time. After 30 days, the residue becomes nearly undetectable. Water speeds up the process as it reduces the half-life to about 45 minutes. If your cannabis plants can continue growing for another month before harvest, a thorough bud wash afterward will remove remaining traces.

FAQs About Cannabis Pest Management

What’s a Good Alternative To Neem Oil for Cannabis Pests?

Growing cannabis is tricky, especially since many pests love this plant. However, there is a concern about the downsides of using neem oils on cannabis crops to control these pests. The good news is that there are neem oil alternatives like Protection Plus, which is an eco-friendly solution. 

Protection Plus is a water-based pesticide that’s designed to control a wide range of pests without leaving residue when used correctly. Unlike oil-based insecticides, it won’t block stomata or cause buildup that leads to insect resistance because the product dries quickly.

This spray works by degrading the insect’s exoskeleton, which causes suffocation. It can be applied in the morning or evening as a foliar spray or soil drench to give cannabis growers an effective, residue-free alternative to neem oil.

What Are The Most Common Cannabis Pests?

Cannabis is highly favored by a variety of pests, which is why many growers need effective insecticides to help protect their crops. The following pests are the most common problems for commercial growers:

• Fungus gnats: Lay eggs in moist soil, and their larvae feed on cannabis roots. They can cause stunted growth and yellowing leaves. 
• Russet mites: These types of mites pierce leaf surfaces. They drain cell contents and may even deform new growth.
• Thrips: They scrape plant tissue and leave behind silver streaks that reduce photosynthesis. 
• Spider mites: These pests spin webs under leaves and suck out chlorophyll that can lead to pale, brittle foliage.
• Whiteflies: Tiny, winged insects that feed on plant sap and excrete sticky honeydew. They can cause sooty mould growth and reduce the plant’s ability to photosynthesize effectively. 
• Mealybugs: They attach to stems and leaf joints, sucking sap and secreting cotton-like wax. Their feeding depletes nutrients, weakens stems, and can transmit viral diseases between plants.
• Caterpillars: These pests chew through leaves, buds, and stems, which creates entry points for bacteria and mould. Their droppings also cause fungal growth, which can destroy developing flowers.
• Inchworms: Consume leaves and young buds that create irregular holes in foliage. Their feeding reduces canopy density and overall energy production needed for flowering.
• Aphids: Feed by piercing leaf veins and extracting sap that weakens the plant’s vascular system. They multiply quickly and can spread plant viruses. They also leave behind honeydew that causes mould growth.

Whether you’re growing cannabis outdoors or in hydroponic systems, pests like fungus gnats and spider mites can still infest your crops. These cannabis pests can cause stunted plant growth, blistered leaves, and even viral transmissions.  

Fortunately, Protection Plus deals with many of these soft-bodied insects and more, including ants, mites, and flies. You can spray your cannabis plants every seven days with Protection Plus as part of your IPM to prevent new infestations.

Read Our Complete Guide To Cannabis Pest Control and find out more safe and effective ways you can remove pests from your marijuana crops. 

Final Thoughts – An Oil-Free Solution That Works 

For cannabis growers who want a clean, eco-friendly alternative to neem oil, Protection Plus gives you a smarter solution. Its water-based formula leaves no residue when used correctly, so it allows plants to breathe and photosynthesize efficiently.

Because it’s non-oily, it won’t block stomata or cause buildup that leads to insect resistance. Protection Plus can be applied throughout the entire growing cycle (morning or evening, every seven days) for consistent pest control. 

It comes pre-mixed, so it’s affordable, easy to use, and reliable for both home and commercial growers. Start using Protection Plus today and experience a residue-free, effective approach to pest management.

Featured image credit: University of New Hampshire