How To Use Natural Neem Oil As A Soil Drench or Soak

There’s a long list of reasons why you should avoid chemical insecticides.

Superbugs, the risk of harming beneficial insects, and other potential consequences often outweigh the potential benefits.

Man drenching potted plants with Neem OilPin

However, neem oil is a natural alternative that’s proven effective against a wide range of pests with minimal risk.

When applied as a soil soak, this already amazing extract becomes a superweapon with all sorts of effects.

Here’s everything you need to know about neem oil for plants and how to make and use your own neem oil soil drench.

What is Neem Oil?

Neem oil is the extract of Azadirachta indica.

The oil is created by cold pressing the seeds, fruit, and other parts of this tree.

In its raw state, neem oil contains a wide range of active ingredients, most notably Azadirachtin.

When the Azadirachtin is removed, it becomes clarified hydrophobic neem oil, which is usually used for topical applications.

Raw neem oil is best used as a soil soak due to the higher concentration of natural chemicals, which csan cause burns on more sensitive plants.

How Does Raw Neem Oil Work?

Azadirachtin is a systemic toxin which affects insects once ingested.

The chemical compound has very similar properties to the insect’s own hormones.

As a result, it tricks the pest into thinking it’s full, causing it to slowly starve itself.

Additionally, it interrupts growth hormones, locking instars from advancing to the next stage.

Finally, it causes infertility in many species, preventing future generations from being laid.

Types of Bugs Neem Oil Kills

Neem oil affects dozens of different insect pests, including:

  • Aphids
  • Beetles and their larvae (AKA grubs)
  • Grasshoppers
  • Mealybugs
  • Scale
  • Spider Mites
  • Thrips
  • Whiteflies

In addition, it has some fungicidal and antibacterial properties.

Using a Neem Soil Soak

There are three ways to apply neem: foliar neem oil spray, neem cakes, and soil drenches.

Of these, soil drenches tend to be the most effective and are a snap to mix and apply.

Why Use Neem Oil Insecticide Soil Soak?

Soil soaks (sometimes referred to as a neem oil soil drench) are perhaps the best treatment method using neem oil. A neem oil spray is great for maintenance.

The neem soaks into the soil, where plants absorb it through their roots.

Once inside the plant, the neem oil becomes a systemic insecticide.

Unlike topical applications, there’s no risk of bees or other beneficial insects coming into contact with it.

Instead, grubs and insects which pierce the plant’s leaves are the only ones affected.

Soil soaks are far more effective and easy to apply on trees and large shrubs than foliar sprays, saving a lot of time and effort.

Even more beneficial, the neem oil boosts your plant’s immune system, effectively fighting some bacteria and fungi.

Best of all, it will remain in your plants for up to 22 days and is non-toxic, so you can use it on crops within a few days of harvesting.

Neem Oil Soil Drench Recipe

Neem soil soaks are quick and easy to make, requiring only three ingredients.

Begin by emulsifying water to break the surface tension and allow mixing with oil.

Simply add one teaspoon of Dawn dish soap or pure castile soap to lukewarm water.

You can use the same amount for either a quart or gallon.

Next, add 1 teaspoon of 100% percent cold-pressed raw neem oil to a quart or 2 tablespoons to a gallon of your emulsified water.

Remember to only make as much as you need, since the mixture will go bad after only a few days.

Applying Neem Soil Soak

Pour 2 to 3 cups of your neem soil drench around the roots of each plant.

Repeat every two weeks to combat an existing infestation.

In the case you are fighting powdery mildew or root rot, watch the plant closely until any symptoms have disappeared.

You may also choose to apply the soil soak every three weeks as a preventative.

It’s usually best to apply neem oil at dusk or dawn when treating outdoor plants to minimize the risk of beneficial insects coming in contact with it.

Note that you can use the same recipe in a sprayer to treat your lawn against grubs.

Neem Oil Insecticide Soil Drench Tips

Always Test First

Neem oil is powerful stuff and contains natural chemical compounds that can leave burns on sensitive plants.

Always apply a tiny amount to the plant 24 hours before the main application to ensure your plant isn’t sensitive or allergic to the neem.

Plants With Known Issues

Carnivorous plants are intolerant to soap, so you will need to add the neem oil directly to water and shake well before using.

Chances are picky plants will have higher sensitivity to neem oil, so be especially careful to test these plants.

Check the label on your neem oil for any plants which are confirmed to be intolerant.

Avoid use on plants which are stressed or have recently been transplanted, as they may suffer additional damage.

Help! The Neem Oil Isn’t Working!

Neem soil soaks work by interrupting the natural biology of insects.

As a result, it’s easy to get frustrated when you’re used to seeing instant results from chemical solutions.

Neem oil, when applied as a soil soak, may take up to two weeks before you begin seeing the effects.

However, once those results become visible, an infestation is well on its way to extinction.