DE & Neem: Two Organic Non-Toxic Pesticides for Your Home & Garden

Elena K, Hometalk Team
by Elena K, Hometalk Team
5 Materials
30 Minutes

Every year, by mid-summer, I see my home & garden turning into a bug-house. Sounds familiar? Luckily, I have plenty of weapons in my pantry and apothecary to take care of the bugs. Today, I want to share with you two of the easiest and most effective in my arsenal: Diatomaceous Earth and Neem Oil. Stay with me to find how to make these wonders!

Got a bughouse? DE & Neem is all you need!
Diatomaceous Earth & Neem are the best!


My two fave weapons in the war against bugs are quite versatile: they work wet, in a spray form, or dry. You can even combine them with other ingredients to enhance DIY boosts and pesticides. Here's what you need to make yours: • Diatomaceous Earth • Neem Oil Health Food Store (Food grade), Online • Spray bottle • Teaspoon and tablespoon or measuring spoons • Biodegradable soap (optional) Ready? Let’s start with the Diatomaceous Earth!

What makes Diatomaceous Earth so special?

Before we dig into how to use DE, I want to share with you why it is such a good, non-toxic insecticide & pesticide. DE is a naturally occurring soft, crumbly, porous siliceous sedimentary deposit formed from the fossil remains of diatoms. It is crumbled into a fine white to off-white powder. It is non-toxic and safe in gardens and with flowers. And it takes care of many insects (including ants) – both IN and OUT the home. Diatomaceous earth works differently from other pesticides by using a mechanical reaction rather than a chemical one. It absorbs moisture from insects’ exoskeletons, so when they come into contact with DE they begin to dehydrate. This will not only kill them but help prevent future infestations as well! There are many places where you can buy DE: from a swimming pool supplier (it’s also used as a filter aid), to your home garden center (Home Depot), health food store (if you’re looking for food grade) and of course online, including Amazon or your favorite health store — I got mine at Swanson, food grade. WARNINGS: Use only food-grade diatomaceous earth, not filter grade. Filter-grade diatomaceous earth may contain high levels of silica and is dangerous to inhale. Diatomaceous earth that is marketed as a pesticide may also contain chemical pesticides. If you want to keep your garden pesticide-free, avoid these types of products and use only food-grade diatomaceous earth.

Baby, I’m just gonna shake, shake, shake!


Now, you don’t want to kill every single insect in your garden – do you? Just need to get rid of pests. Diatomaceous Earth to the rescue! There are two ways of using it: wet or dry. Let’s start with the DRY METHOD. 1. Fill a shaker or mesh shaker with diatomaceous earth. A mesh metal strainer or a flour sifter will also work. TIP: Wear a face mask if you’re working with large quantities or have respiratory issues. 2. Shake the powder and lightly dust onto the vegetable plants or dry areas of your garden: The powder can be easily washed off the veggies before consumption. TIP: Do not use a thick layer of diatomaceous earth on the leaves of vegetable plants. It can block sunlight and interfere with photosynthesis. And consider using the WET method if it’s too windy (STEP 4). 3. You can also apply it to the garden bed and areas surrounding the garden. This will keep many crawling insects from even reaching the vegetable plants. 4. For extra protection, pour a thick ring of diatomaceous earth around the base of plants to deter SNAILS, SLUGS and SQUASH BUGS. TIP: The best time to apply it is early morning or late evening, when the plants are wet with dew. The moisture helps the dust adhere to the plant. You can also spray the vegetable plants with a garden hose if it’s too hot for morning or evening dew. Wait until the excess water drips from the plants, and then shake the powder on the damp plants. NOTE: Diatomaceous earth won’t harm insects. But it won't be effective while it is wet, only once it dries.

Spreading DE love is easy!


Get your diatomaceous earth, a pair of disposable gloves and a mask (optional). Pinch a little and put it along the door entrances, window encasings, or other areas you want your protect. TIP: Remember it’ll only work when dry. So reapply once a week, or earlier if it rains.

Let’s use a DE spray for larger areas!


You can also dilute the Diatomaceous Earth in water and apply both in and outdoors. It will only work once the water has evaporated, and may be a little messier, but will allow you to target larger areas. TO MAKE A WET SPRAY: Add 4-6 tbsp of DE to 1 GALLON of WATER. I’m using 32oz so 1-1 1/4 tablespoons is good. TIP: Use a small funnel or a piece of paper to ensure the DE powder doesn’t spill out of the mouth of your bottle.

Let’s label the DE spray before we use it!


Grab tape, a pen and bottle and write down the NAME, DATE, and INGREDIENTS. TIP: If you mixed the powder directly into the spray bottle, add amounts to ingredients. If you’re using a larger container to store your mix, write amounts here, but also label your spray bottle. You want everyone in the household to know what's in that spray bottle!

DE spray is perfect for larger or windy areas


Fill a spray bottle with the mixture. Shake and spray once or twice, at a 1’-2’ distance from the area you want to protect. Spray the plants until they are wet but not dripping. This method works well for TREATING ALL PARTS OF THE PLANTS with diatomaceous earth. TIP: Spray the undersides of leaves as well. The water “glues” the powder to the plants. Once the plants dry, they will have a thin, even coating of powder. TIP: The SPRAY METHOD works well if it's WINDY, when it'd be difficult to use the shaker to dust the plants.

Yes! Can you believe it also works with ants?


DE is also effective to fight ants. Apply wet or dry to eliminate and prevent ants. (See STEPS 3, 4, 5 and 7) You can also apply directly onto an ants’ nest. I haven’t tried this method—luckily I never needed to! But I thought it was worth it to include here: To target a nest, you need to open it and eliminate the queen. Use a shovel to open it and get to the tunnels as well. Then apply a good amount of DE to the area, including the area within a one-foot radius. Find more info on ants and how to make a Sweat DIY bait in my previous post:

Neem: An ancient oil that works like a charm!


Neem can safely be used on food, leaves no dangerous residue in the soil and effectively reduces or kills pests, as well as prevents powdery mildew on plants. But wait. First, WHAT IS NEEM OIL? Neem oil comes from the tree Azadirachta indica, a South Asian and Indian plant commonly used as an ornamental shade tree. Neem oil can be extracted from most parts of the tree, but seeds have the highest concentration of the insecticidal compound: Azadirachin The oil has many traditional uses outside of the insecticidal traits but gardeners hail it for its anti-fungal and pesticide properties. For centuries, seeds have been used in wax, oil and soap preparations. It is currently an ingredient in many organic cosmetic products too. I use it to make soap, and it works great to treat skin conditions!

Time to make a Neem Oil Spray!


Neem oil spray is effective to eradicate soft bodied insects such as APHIDS; CATERPILLARS; GLASSY-WINGED SHARPSHOOTER; LACE BUGS; LEAF-HOPPERS; MEALYBUGS; PLANT BUGS; PSYLLIDS (which attack pear, potato, tomato and citrus); SOFT SCALE; MITES; THRIPS; and WHITEFLY. Grab your spray bottle, neem oil and Bronner’s soap (optional.) TIP: Dr. Bronner's liquid soap as a surfactant and it’ll help the oil to dissolve and mix more easily in the water. TO MAKE THE SPRAY: Mix 1-2 teaspoons of neem oil per gal of water, and spray every 4-7 days, for up to 4-5 weeks. Add up to 1/8 spoon of Bronner’s soap. For me, 1/8 teaspoon or 30-36 drops of neem oil per 32 liquid oz. Add a few drops of Bronner’s soap. We’re almost done! But before we apply Neem Oil Spray, let’s label the bottle: Grab tape, a pen and a spray bottle and write down the NAME, DATE, and INGREDIENTS. TIP: Don’t forget to include amounts in your ingredients.

Let’s give our plants a lil' Neem Love!


Neem oil spray has a short shelf life. Apply the spray within 1-2 days of making it, ideally within the first few hours. TIP: Make smaller amounts more frequently! Do not use neem oil in extreme temperatures, either too hot or too cold. Avoid application to plants that are stressed due to drought or over watering. TIP: Apply neem oil only in indirect light or in the evening to avoid the product burning foliage and allow the preparation to seep into the plant. Using neem oil insecticide about once a week will help kill pests and fungal issues as bay. Apply as you would other oil-based sprays, making sure the leaves are completely coated, especially where the pest or fungal problem is the worst. It is nearly non-toxic to birds, fish, bees, ladybugs, butterflies and wildlife, and studies have shown no cancer or other disease causing results from its use. This makes neem oil very safe to use if applied properly. CAUTION: Before spraying a an entire plant, TEST A SMALL AREA on the plant and wait 24 hours to see if the leaf has any damage. If there is no damage, then the plant will not be harmed by the neem oil. Some plants can be killed by neem oil, especially if it is applied heavily.

Time to make the Neem Soil Drench!


Making a Neem DRENCH is easy! Just add 4 teaspoons of Neem oil per gallon of water. You can also add and 1 teaspoon of Bronner’s soap. TIP: Add 1 teaspoon of an ecologically friendly dish detergent (Bronner’s or other biodegradable soap) to the water as a surfactant. Before you use the drench, grab tape, a pen and spray bottle and write down the NAME, DATE, and INGREDIENTS. TIP: Don’t forget to include amounts in your ingredients list.

Let’s use the Neem Soil Drench!


Use the drench to water your plants — as you’d use regular water — if you suspect an infestation, such as gnats. Water early in the morning or evening. TIP: Again, do not use neem drench in extreme temperatures, either too hot or too cold. And avoid application to plants that are stressed due to drought or over watering. And I think that makes it for pest controls! If you haven’t yet, check my “3 Household Items to Keep Your Garden Pests at Bay” post— — and Get Rid of Your Ants With a Sweet DIY Treat post — And follow me for updates on my latest posts and to find what's cooking.

Suggested materials:
  • Diatomaceous Earth   (Pool Supplier, Home or Garden Center, Health Food Store (Food grade), Online)
  • Neem Oil   (Health Food Store (Food grade), Online)
  • Spray bottle   (Dollar Store, Home Center)
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Frequently asked questions
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3 of 6 questions
  • Jet15263900 Jet15263900 on Aug 07, 2017

    Can you please sign me up for your newsletter.

    My email address is.

  • Eddie Figueroa Eddie Figueroa on Aug 13, 2020

    What do I use first?!? Neem oil then diatomaceous earth? Does it matter? Which way is more effective?!

  • C E C E on Sep 14, 2020

    Does neem powder work like the oil?

Join the conversation
2 of 5 comments
  • Kelly Howard Kelly Howard on Jul 27, 2017

    Food grade DE is also good for humans. It detoxes much like activated charcoal. Farmers use it in animal feed to keep their animals healthy.

  • Carol Williams Carol Williams on Mar 02, 2020

    In step two it says will not harm insects but i was thinking that killing the insects was pretty much the point of using it. Maybe I’m reading it wrong?