How to Use Neem Oil on Plants

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Neem oil is an organic pesticide that is safe for pollinators and plants yet can help you control insects, pests, and fungi in your garden. In this post, you’ll learn how to use neem oil on plants.


I truly believe that with correct garden care you can prevent most of the problems that can come up in the garden like fungi, mold, pests, and rot.

However, sometimes there are stubborn bugs and difficult weather conditions that are not in our control. These garden guests and uncontrolled conditions can sometimes cause the loss of crop that you worked really hard to grow.

Every gardener should have a few “emergency” solutions ready just in case and if you are an organic gardener, you’d probably prefer the solution to be an organic one and one that is safe for the environment.

And that’s where neem oil comes in!

How to Use Neem Oil on Plants…

Neem oil is an organic pesticide that is safe for pollinators and plants yet can help you control insects, pests, and fungi in your garden. In this post, you'll learn how to use neem oil on plants.  
#neemoil #neemoilingarden

If you make sure to improve your soil, to space your plants correctly, to prune your plants (if there is a need), to fertilize them with worm castings or another organic fertilizer, or if you make sure to add a lot of compost to your beds yet you still find yourself losing plants to mean and unwelcome pests, mold, or fungi, neem oil might be a great organic solution.

What is Neem Oil?

Neem oil is pressed from seeds obtained from the neem tree (Azadirachta indica) which is native to India. Its color varies from yellow to brown and it has a garlic/sulfur smell to it. The most active component in neem oil is called Azadirachtin, it has the ability to repel and kill pests.

Neem oil uses are not limited to the garden alone. It is used in preparing cosmetics, and in traditional Ayurvedic medicine (mostly for skin diseases, fever, and inflammation), however, in this post we’ll focus on how to use neem oil in the garden.

Is Neem Oil Safe?

Japanese beetle on bean leaves.

Neem oil is non-toxic to birds, fish, mammals, bees, and plants.

Neem oil will not harm bees and other beneficial pollinators because it’s only harmful to pests when they eat it. Since bees and other pollinators don’t eat the sprayed leaves of the plant, neem oil won’t hurt them.

If you come in contact with the neem oil that you bought for your garden, it can cause irritation and redness to your skin but other than that it’s not harmful. Take into consideration that children’s skin is a bit more sensitive than adult skin.

Neem oil is also safe to spray if you have cats and dogs around. Since they don’t eat the garden plants they’ll be safe.

Where to Buy Neem Oil?

Neem oil and a spray bottle.

You can find neem oil in most garden centers during the spring and summer. You will most likely find it at stores like Walmart for example. If you want to purchase it online, you can find it on Amazon here.

Neem oil usually comes in a small bottle in a concentrated liquid form. You then mix some of the oil with water to create a diluted spray that you spray on your plants. So make sure that you have a spray bottle that you can use (I usually use a one-gallon pump sprayer).

Neem Oil Uses…

Neem oil can be used as an organic pesticide in the vegetable garden, flower garden, or even on fruit trees. It can’t be used as a herbicide (to control weeds).

Colorado Potato Beetle.

Neem oil as an insecticide – like I mentioned before, neem oil can be used to kill insects that eat the leaves of garden plants like the Japanese beetle, the Colorado potato beetle, aphids, and so on.

Once insects eat the sprayed plants, the oil damages their digestive system and makes it hard for them to eat. It also has a negative effect on their hormones making it hard for them to reproduce. After just a few hours, they’ll die.

The smell of neem oil will also repel many insects from landing on your garden plants.

Neem oil as fungicide – neem oil is also helpful against root rot, black spots, mildew and scab, fungi, and mold. It can also be used to control bacterial diseases like fire blight.

The bottom line is that neem oil is safe for plants and won’t harm beneficial insects so if you find that you have a problem in the garden that you can’t find a solution for, maybe a sort of mold or an unrecognized insect, you can try spraying neem oil since it can be beneficial in many situations.

How to Mix Neem Oil For Plants…

Diluting neem oil.

Mix 2-3 tablespoons of neem oil into a gallon of water. It’s best to use a sprayer that is set aside just for neem oil.

How Often to Spray Neem Oil?

The only downside of neem oil is that it breaks down quickly.

The National Pesticide Information Center states:

The half-life of azadirachtin in soil ranges from 3 – 44 days. In water, the half-life ranges from 48 minutes to 4 days. It also rapidly breaks down on plant leaves; the half-life if 1 – 2.5 days.

This means that it’s best to spray every few days. You’ll also have to spray after every rainy day because the rain will wash the neem oil off the plants leaves.

Another reason to spray every few days is because neem oil doesn’t kill the insect’s eggs so you’ll want to keep spraying and killing the new ones that hatch from the eggs.

It’s also best to spray on a non-windy day and wear long sleeves, gloves and glasses. Make sure to spray the tops but also the bottom of the leaves since many insects live there and lay their eggs there.

I usually don’t spray baby plants. I wait until the plants are at least 8 inches tall before I start spraying them.


Neem oil is a very easy solution for the organic gardener. If you make sure to have a dedicated sprayer for it and have it close to the garden, it’s easy to spray every few days and keep the insects under control.

If you have experience with neem oil, please share it with us in the comments below.

If you liked this post, check out my other gardening posts…

How to Grow Mint From Cuttings

How to Plan a Vegetable Garden

Best Vegetable Varieties to Grow in a Kid Friendly Garden

Grafting Fruit Trees – A Step by Step Picture Tutorial

The Garden Workbook is Here!

In part one of this book, we’ll go over how to set up and grow your best garden yet.

Part two consists of 16 garden printables to help you plan, record, and manage your garden properly!

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20 thoughts on “How to Use Neem Oil on Plants”

  1. I have a bush cucumber that has yellow spotting like yours. I haven’t sprayed anything on or around it. I thought maybe the dog peed on it. It was fine yesterday. The plant still looks to be growing good still and it’s loaded with blooms, so it’s a mystery to me too.

    1. You know, I washed my cucumber plant after I noticed the spots. I figured I’ll get the neem oil off of it. But tonight I noticed a few more leaves with yellow spots. I am starting to think maybe it’s bugs and not the neem oil… I am just going to keep an eye on it and see what happens. I have a ton of blooms too, but I only had 1 cucumber so far. I see a few coming along, we’ll see if they actually mature. Keep me updated on your plants, let me know if they producing or dying.

  2. A few years back I used Neem oil as a leaf polish. Some of my front yard Asters got that grey mold from being damp, it glossed them up. I used it one other time on my Italian plum when it got hit with aphids, it killed the aphids but it wiped out the leaves too. This year I didn’t do anything about the aphids and the beneficial bugs have shown up like an organized army. (I do pray a lot!) Back to your potatoes, you might want to consider using a row cover and keep the straw mulch back where they can’t use it to hide in. I gave-up using straw or any compost that is not to “full-mulch” status, it harbors way to many bugs & slugs. I advocate the use of Diatomaceous Earth (DE). I dust my seed potatoes when planting in ground and dust the top soil to discourage any crawling & digging. I use this DE top-soil-dressing with other garden plants also and it works great. (Knock on wood) I came in for lunch from digging potatoes and found this in my email. Take care of yourself Lady Lee! Keeping you in prayers!

    1. I got DE for the first time when I got the neem oil. I never used it before and wanted to try it before I write about it. I dusted it on the soil/hay mulch around the pumpkin plants the other day. I am waiting to see if it’s going to help them a bit. A couple of days ago I had to pull another one out. Back in my garden in the city I didn’t have so many problems with bugs, I am wondering why here in the country there are so many of them.
      Will definitely use the DE on my potatoes next year. And maybe I need to do more praying 😉

      1. Back in the city/towns there are more people, many of those people use chemicals in their yards & gardens. Almost all my neighbors use chemicals for bugs & weeds. Once you get to my fence line, it all changes and it’s abundant with life (the good, the bad & the ugly) and flora except!….I have no frogs, crickets, garden snakes, rarely a butterfly and the Robin population has about disappeared and the Black Bird population and grasshopper population has increased. The population here don’t like to work in their yards, they have mostly perennial shrub, flower, tree, seasonal bulbs, beauty rock & bark and they spray like crazy to keep it weed free. Most of them hire gardeners so the more “moon scaped” it is the less it cost to care for. Also less ground cover crops for bugs to live in. You might want to do several experimental garden plantings next year. Say split your potato plantings, a quarter planting under protective row cover cloth, another planted “furthest away” from your garden as a “lure & entrapment” to the bad bugs, and a couple more using heavy inter-planting of different annual flowers that attract beneficials that prey on your crop predators. I’ve used wood ashes & DE as early spring barrier lines with my neighbors slug & snail and have had huge success. I direct seed and sink plastic milk jugs (mini greenhouses) around the planting, then put down a protective ash/DE barrier around the jug. You can use these natural barriers for your fruit trees also.

        1. I love what you are doing in your neighborhood. I went to a Florida Yards and Neighborhoods class and I realized if I xeriscape and plant natives for the wildlife to eat and hide in I will be overrun with wildlife. My neighbors are like yours. Further complication is I happen to be at the entrance to this development and although they have no enforceable Association, they will never accept the jungle look of my yard.
          I have completely natural pest control
          and use no herbicides either. 15 years!! I love my yard, which changes with the wind, literally!
          Most people I show pics can’t believe how lush it is.
          Now I still have a few non natives or I could have my yard “certified” and teach a class.
          Please, everyone try all natural and watch the magic happen?

  3. I do not garden as you or a good many of your readers, but I do so enjoy what you write and how you educate and receive education from others. The caring between all who read your blog is heart-warming. Take care of yourself and prayers for an easy delivery and happy/healthy baby and you.

    1. Thanks Logan! I learn so much good information from my readers. I love the interaction because sometimes it’s hard to meet people who “gets” you.

  4. Hey, we just moved to NC from the Norfolk area. We are trying our hand at farming, gardening and homesteading. Are you in the Coastal area of the state?

      1. No darn it! We’re about 3 hours apart. Close enough to have the same garden pests. I planted radishes around my cukes, to just grow there, not to eat. I read somewhere that’s suppose to keep the bugs away. I haven’t had any bug damage. I have had those yellow spots on the leaves and some oddly formed cubes. I’ve read those spots might be from too much water or inconsistent watering. We had a long spell of really hard rain about every three or four days then, no rain for five or six days. I’m thinking it’s a watering issue.

        1. You know, I didn’t think about watering issues… We have some crazy wet weeks here and then a week or two without rain at all and 100F, this might be an issue.
          I thought about planting garlic everywhere… I mean in between all my plants. No pest likes garlic, maybe it will work. Last year I had three cucumber plants right here across from where we live right now on our 20 acres. They produced so many beautiful cucumbers! This year I planted more thinking I’ll have a lot to pickle, but then… Nothing. I will be harvesting the second cucumber of the season tomorrow. The second! And it does look funny. Oh well, that’s the life of a farmer I guess. If you are coming this way let me know. You are welcome to stop by!

  5. I am trying Neem Oil for the first time this year. I have sprayed around the plants and tested on a few leaves, so far everything looks OK. Need to spray again today because hot — forecast about 96 degrees today — and humid — well over a 100% — has been and is the forecast for the foreseeable future. I have lost all but four tomato plants. They turned brown and rotted at stem next to ground. Pulled one and there were worms galore in the roots. Pulled the others and not worms. I think they may have been traveling worms. Question: Can Neem Oil be sprayed directly on the roots and surrounding the roots to kill worms. Thinking about pulling back some of the dirt and saturating the ground with Neem Oil. Another Question: I am also experimenting with Diatomaceous Earth (DE) for the first time. In doing research, some say do not ever get it wet because then it won’t do any good. Others say mix it with water to make a slurry and spray it wherever. Please advise. Thanks.

    1. It happened to me with zucchini last year. Rotten at the soil level, the whole plant was gone very fast. I sprayed neem oil in the stem close to the ground and sprinkled DE too. I repeated that after every rain or once a week if it wasn’t raining. It did the trick and I didn’t lose all of my plants.

  6. Hi Lee,
    I’m loving your blog too, and learning SO much! We are new to homesteading…and trying to set up our 10 acres…very challenging to say the least! Super rocky soil seems to be everywhere and now we have the hot summer hitting. Thankfully, our jujube trees are quite happy in these conditions. My question is on the milk jug thing. Are these filled with water, to slowly drip? Or are they merely barriers or both? We are starting raised beds, since our veggies won’t likely ever grow in this soil. Also, what kind of mulch do you find is best? We’re hoping to get a large compost pile going soon, but don’t have one yet, so will have to supplement with purchased bags…expensive though dang-it!

    1. Lynn, direct me to where you saw the milk jug thing… I am not sure what you are talking about.
      I love straw the most. BUT, you have to let it sit in the elements for a couple of weeks and make sure the bales are rained on before you use it. If you use it right away and there are seeds in the bale, they will germinate in your garden and it’s a pain to weed it out.
      If you open the bale and let it sit in the rain and sun for a couple of weeks, whatever needs to germinate will germinate and you can remove it before you use the straw.
      As far as compost goes… Since you have 10 acres I assume you are in a rural area. Try to find someone with cows. They usually have mountains of poop and it’s all you need. Usually they are happy to give it away.
      Make your raised beds and fill them with cow’s manure, plant right into it. This way you don’t even need soil.

  7. Lee:
    I found the solution to Colorado potato beetles years ago. At the first sighting, pick off a handful of beetles and larva. Mix them with water in your food blender. Strain out the solids using cheese cloth and transfer the beetle juice to your sprayer. It will only take a day or two for the beetles to die and fall off. Not sure exactly why this works, but suspect it releases beetle specific viruses or bacteria which kill the remaining mob infestation.

  8. some pests are eating my lilac bushes and I can’t find a cure. Would Neem Oil be a cure?
    I cut them down to 6 inches above the ground
    and now they are growing beautifully;; however, last year the bugs ate all the leaves.
    What’s a mother to do?

    1. You can definitely try neem oil! Wait until the plant is a bit bigger. You can wait until you see the bugs or spray once every couple of weeks even before you see them. The smell might keep them away. Remember that you have to spray after the rain. Good luck!

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