Spider mites are an unusual pest, with bodies resembling ticks, but the ability to create messy webbing that resembles that of spiders.
This family of arachnids tends to infest indoor plants more than outdoor plants, where they’re easily preyed upon by natural predatory insects, birds, and other hunters.
Due to their tiny size, you might not even notice their pepper-like appearance until messy webs begin appearing between the leaves and stems of the infested plant.
Although most species range in color from black to a deep reddish-brown, two particularly frustrating species bear the nickname of red spider mites, with European red spider mites preferring apple trees and southern red spider mites preferring whatever houseplant you love most.
Spider mite infestations tend to hide on the undersides of leaves, making them harder to spot.
These plant pests pierce your plant and drink the sap, becoming especially problematic in hot or dry weather.
The webbing is used for both protection and as highways to get from one part of the plant to another.
Spider mites can also spread on wind currents to other plants.
But the worst part is that it only takes 5 days for a spider mite to develop from egg to fertile adult, with three molting stages in between.
Neem oil is one of the few completely natural remedies that can kill spider mites, but improper application can reduce or negate any effectiveness.
The following methods are geared primarily towards indoor plant but may be adapted for outdoor use as well.
How To Use and Mix Neem Oil To Kill Spider Mites
As mentioned, neem oil must be mixed and applied properly to achieve the best results.
Because spider mites breed fast, isolating an infected plant along with any neighbors, using a combination of methods is generally the best solution.
How Neem Soil Soak Affects Spider Mites
Neem soil drenches or soaks are incredibly effective against spider mites, as it uses 100% percent cold-pressed raw neem oil, which has the highest concentration of Azadirachtin.
The soak is absorbed into the plant, turning the Azadirachtin into a systemic insecticide.
Azadirachtin is a natural chemical found in the neem plant (Azadirachta indica) that closely resembles the hormones in insects that regulate growth and reproduction.
When a spider mite nymph ingests Azadirachtin, it may lose interest in feeding, and its ability to reach the next growth stage can be hindered or even halted.
Meanwhile, an adult may become unable to lay eggs or become infertile.
Neem soil soaks won’t directly kill most of the spider mites, but will instead prevent them from aging or reproducing and cause the infestation to die out without harming beneficial insects or pollinators.
Related: Are Soil Mites Good Or Bad?
How to Make and Use Neem Soil Soaks
It’s easy to make your own soil soak, and it only requires three ingredients, two of which you already have at home.
- You will need to emulsify water, which requires one tablespoon of Dawn dish soap or pure castile soap per gallon of water, gently blended in. This allows the oil to mix with water by breaking the surface tension.
- Next, add two tablespoons of raw neem oil. Be sure to only buy raw neem oil that has been cold-pressed, as heat can affect the oil’s potency.
- To use, simply pour 2 to 4 cups of the soil soak solution to the soil of your plant in place of normal watering.
Learn more about Mixing Neem Oil for the garden and plants.
Once applied, a single dose will last for up to 22 days, and can be reapplied every three weeks to fight off active infestations or monthly as a preventative.
How Foliar Neem Oil Sprays Affects Spider Mites
Neem foliar sprays use clarified hydrophobic neem oil, which is created when Azadirachtin has been extracted from raw neem oil.
This version still has several active components, but has a very different effect and is used as a contact poison.
Instead of stunting an insect’s growth, clarified neem oil gets into the bug’s airways, causing it to suffocate.
More On: Learn How Neem Works on Plant Pests
Clarified neem oil is available in .5 to 3% percent potency levels, allowing you to choose the strength that works best for your needs.
Because the foliar spray is topical, it shouldn’t be used outdoors during times of day when beneficial insects are active.
However, it may be used indoors at any time of day and will evaporate without any residue after 45 minutes to an hour.
How to Make and Use a Neem Foliar Spray
As with the soil soak, you only need three ingredients.
Begin with emulsifying water the same way as you would with a soil soak, then add four teaspoons of clarified neem oil.
Using a spray bottle, coat the entire plant, getting every crevasse and making sure to get the underside of every leaf.
Any nymph or adult spider mites that are coated will soon die, although it won’t kill the eggs.
You will need to do a fresh application every 2 days for 14 days or until the infestation is gone. Afterwards, you can apply the foliar spray every 2 to 3 weeks as a preventative measure.