How to Get Rid of Spider Mites on Weed Plant | Kill & Prevent Them From Returning!

Spider mites are a marijuana grower’s worst nightmare.

A spider mite infestation can wreak havoc on your personal grow room, garden, and greenhouse.

These pests especially have an appetite for soft greenery, such as a cannabis leaf.

What should a beginner weed planter do against such a menace?

Thankfully, this guide here will show how to defend your marijuana crops from these pests.

How to Get Rid of Spider Mites in 10 Different Ways

Through early identification of an infestation, you can easily remove spider mites naturally from your plants, especially during the flowering season.

Here are the different ways you can do it:

1. Insecticides

You can drench chemical or organic insecticides over your plants to eliminate spider mite arachnids in the grow room.

You can spray the garden for 15 minutes before going to sleep.

It would be best if you drenched the cannabis leaf, the foliage underneath, and even the topsoil with the product.

You can even use a fan to blow the insecticides dry.

For pet owners and families, you can use products made from spinosad, a specific fermented soil bacteria, because they are organic and completely harmless to pets, children, and plants.

While the product still kills spider mites on contact and other marijuana pests.

For a weighty infestation of spider mites on weed, consider using broad-spectrum insecticide for complete room treatment or even the entire grow room but only as a last resort.

IMPORTANT NOTE: Avoid sprays or miticides with Abamectin or Lindane as they harm humans.

2. Vacuum Cleaner

A simple handheld vacuum cleaner can pass over the top and underside of plants to suck up all the lifecycle stages of spider mites.

After collecting the pest swarm, you simply transfer the contents into a disposable sealed plastic container and a freezer.

The extreme cold will kill all the spider mites in all their lifecycle stages, after which you dispose of them in the trash.

3. Insecticidal Soaps

Insecticidal soaps are made from fatty acid salts, which weaken a spider mites’ outer shell but are human-friendly and don’t leave much residue.

Coverage is essential when it comes to applying soaps to plants.

NOTE: The product doesn’t last long on plants as they need re-application.

4. Diatomaceous Earth

Diatomaceous Earth is a kind of fossil dust made from algae, which you sprinkle on top of your soil and anywhere else indoors.

The dust is also food-grade and is entirely harmless to mammals and plants.

Diatomaceous Earth kills spider mites by tearing and drying them out on contact as the dust is sharp on a microscopic level.

However, the dust can not remove an entire infestation, only manage and hinder its growth when effectively used.

5. Remove or Quarantine the Plants Entirely

Leaves with heavy infestations need to be removed and isolated into a disposable plastic bag with a good seal.

Throwing out the plant is the best course of action that will prevent any further infestation.

Be sure to isolate any new plants from spider mites for at least 2 weeks due to their tiny size.

6. Spraying Pressurized Water on the Non-Cannabis Plants

Use a faucet or hose to wash the stems and leaves of sturdy non-cannabis plants with pressurized water to wash away any eggs or pests.

Start by isolating the infected plant and then spray thoroughly, rinse and repeat if necessary.

7. Neem Oil

Neem oil is a naturally occurring pesticide safe for treating flowering plants.

However, the product doesn’t smell nice and can leave an unpleasant taste on the buds.

Neem oil can be potentially harmful to people by causing allergies to specific people.

The product is only hazardous when consumed in large quantities, causing vomiting, liver damage, metabolic acidosis, and even encephalopathy.

8. Homemade Recipes

For the budget-conscious, homemade recipes can be used to get rid of spider mites.

In a spray bottle, a bleach solution is a mixture of bleach and water at 95 degrees Fahrenheit.

This is especially useful for indoor grow rooms as it can double as a surface cleaner.

Alcohol and water mixture can kill insects on contact and is safe for the plant. These ingredients and solutions can even create a homemade pepper spray.

9. Essential Oil

You can prevent spider mites with essential oils before and after infestation.

The diligent application of the essential oils for several weeks can effectively stop the life cycle of spider mites from damaging their central nervous system.

  • The INFESTATION PROTOCOL is 2.0 oz of your choice of essential oil or crop control per gallon every 72 hours until the infestation is stopped. Then, you switch to a weekly application of 1.0 oz per gallon.
  • The PREVENTIVE PROTOCOL is 0.5 oz per gallon once per week, and 1.0 per gallon is applied for 2 weeks before the harvest of cannabis plants.

You can apply the product until the day of the harvest of fruits and vegetables.

REMEMBER: Wash your crops before consuming them to be cleansed of any residual product.

Well-established spider mite infestations can be hard to remove due to their protective webby canopies.

You need a handheld vacuum cleaner to remove the protective webbing before applying the spray.

10. Biological Control and Natural Predators

Biological control or biocontrol controls pit the predatory insects or, specifically, the natural predators of spider mites to protect your weed plants.

Biocontrol acts as a great alternative to harvest for your crops near or when using chemical sprays is out of the question.

You can also leave natural predators to kill spider mites around your plants.

You must be careful with your choice as you must look for a specific predator to match a season for optimal growth.

For example, you would need ladybugs during the fall season as they thrive during the year’s colder months.


Phytoseiulus persimilis, or the Phytoseiulus, is a predatory mite that excels in getting rid of spider mites, specifically the two-spotted spider mites.

They are active all year round and can feed on a spider mite’s life cycle stages.

The ideal condition for phytoseiulus is the minimum temperature of 82 degrees Fahrenheit.

Be sure to flag all the active colonies of spider mites to introduce phytoseiulus. Take note of small block dots among cannabis leaves and how effective phytoseiulus kills spider mites.

Phytoseiulus should be introduced every week until the spider mite problem has been healthy for 3 weeks.

Release phytoseiulus depending on how heavy the infestation is, 1 or 10 for every lightly infected cannabis plant and 10-100 for heavily infected marijuana plants.

Miscellaneous Tips for Phytoseiulus Use

Another practical preventive choice is the neoseiulus californicus, especially when you have difficulty finding spider mite populations.

The phytoseiulus works because prey is not required for this species to survive.

Ideas to keep in mind as you protect your cannabis plant.

  • Begin early to control the two-spotted spider mite population
  • As phytoseiulus get rid of spider mites, the predatory mites will eventually starve themselves as prey disappears
  • Increase the rate of release proportional to the spider mite population over the next 2-3 weeks
  • Place the predatory mites over plant hangers, weed plants, or infested other plants

4 Steps to Get Rid of Spider Mites on Your Weed Plant

Spider mites are a common cannabis pest that can be challenging to remove.

After learning the different methods above, it’s time to follow these simple steps to get rid of spider mites from your weed plant:

Step 1: Use a Method of Choice to Kill All the Spider Mites

Before you start removing the plague called spider mites, there is some prep you need to do first.

You can reduce their number by controlling the heat, as spider mites love it hot and dry.

A slight breeze won’t blow them all away but make it harder for them to reproduce as you place a nearby fan.

Air circulation as pest prevention works not only on spider mites but affects other bug varieties too.

Here’s a quick recap of the methods you can use to kill spider mites:

  • Insecticides
  • Vacuum Cleaner
  • Insecticidal Soaps
  • Diatomaceous Earth
  • Remove or Quarantine Plants Entirely
  • Spray Pressurized Water on the Non-Cannabis Plants
  • Neem Oil
  • Homemade Recipes
  • Organic essential oils
  • Biological Control & Natural Predators

Step 2: Use a Different Method to Get Rid of Spider Mites

After 2-3 days, use a different method of spider mite extermination to kill any remaining eggs and adults.

Any remaining adults may have grown a resistance to your initial attempts, so a different one can potentially finish the job.

Step 3: Repeat Steps 1 and 2 at Least Once

Repeat steps 1 and 2 at least one more time to clean out your grow room or greenhouse.

Some species of spider mite can return stronger in a few weeks after growing immunity and resume terrorizing your cannabis plant again.

Some species are more resistant to your initial methods to get rid of spider mites.

Hence, you double down on areas freshly cleared of spider mites to be sure.

Step 4: Prevention

Once you get rid of the spider mite family growing in your garden, it’s best to prepare for any potential return.

Your preventive measures reflect whether you keep your crops and vegetables indoors or outdoors.

What Are Spider Mites?

Spider Mites are one of the most common outdoor herbivorous pests, with over 1200 different sub-species under the Tetranychidae or arachnid family.

These arachnids live in colonies frequently found on the underside of leaves.

Spider mites can be found across North America, terrorizing outdoor and indoor plants; greenhouses are especially vulnerable.

Spider mites are so small that they are impossible to see with a human eye; males are only 0.5 millimeters, while females are only 0.4 millimeters.

Their presence is only alerted to the destruction they leave behind. A plant with a few spider mites on its leaves is enough of a sign of an already-infested plant.

Spider mites thrive in arid conditions or areas sprayed with chemical insecticides.

The chemicals ironically kill spider mites’ natural predators, allowing them to spread uncontested.

Red Spider Mites

A known subspecies of spider mites is the red spider mite.

Red spider mites attack various garden plants, particularly Camellias and Azaleas.

The red spider mites are further divided into 2 TYPES:

  1. Apple Tree infesting European red spider mite
  2. Southern red spider mite

By learning to identify spider mites, you can prevent spider mites from critically damaging or even killing your plants.

What Do Spider Mites Look Like?

Spider mites are so small that gardeners can only view them under a 10x magnifying glass.

The best way to find spider mites is by examining the damaged leaves of a marijuana plant and other plants for holes and webbing.

A known sign of spider mites is a dusty underside of a leaf. The dust underneath is the spider mites themselves.

Another sign of spider mites is webbing around plant branches or on the underside of the leaves.

Adult spider mites have oval-shaped bodies with bristles all over them.

Their juvenile stage is pale green, with dark green spots spreading as they mature.

Most spider mites come in colors that help them blend in with plants, such as reddish orange, green, yellow, black, translucent with spots all around, and many more.

What Is the Life Cycle of Spider Mites?

The life cycle of a spider mite’s ideal conditions is DRY, below 50% humidity, and 80 degrees Fahrenheit or more.

5-7 days is all needed for a spider mite egg to reach full adulthood in ideal conditions.

Their maturity process occurs around June to September, only increasing the cycle to 19 days around spring or fall.

Spider mite eggs hatch after 3 short days after adult females lay millions of eggs in ONE MONTH.

Soon, a million mites will reach sexual maturity in a week and make just as many spider mites.

A spider mite population can decrease through regulated humidity and temperature, especially within a greenhouse.

The shortened sunlight hours cause female spider mites to enter a stage of halted maturity or diapause.

In that state, female spider mites are orange, infertile, won’t eat, and most importantly, won’t lay eggs.

Where Do Spider Mites Come From?

A spider mite infestation can come from anywhere.

Spider mites are attracted to areas with low humidity and warm temperature.

A plant with broad, soft, and thin tissue, such as cannabis leaf, primrose, hibiscus, etc., attracts spider mites.

The most common methods of spreading include the following:

  • Being carried away by the wind into your wee plantation
  • Spreading from an infected plant/”zombie” plant that is mixed with non-infested plants
  • Hidden amongst soil that is about to be added to your garden
  • Pets, other animals, and even people’s clothes and footwear can act as carriers for spider mite eggs or adults
  • Unwashed and unsterilized equipment can also carry these pests

What Does Spider Mite Damage Look Like?

Spider mites feed by piercing leaves and sucking liquid from the tissue within.

Spider mite bites on a plant leaving behind a yellowed discoloration with white, tan, or yellow spots.

Infected plants with webbing is another sign of spider mite damage. The webbing appears as a cottony white on the underside of the leaves.

The damage left behind on leaves is seen as tiny specks so small the human eye can’t see them. The damage is often left unnoticed, leaving the spider mite infestation to spread further.

When spider mites feed, a significant swathe of plant cells is devoured. A giant spider mite infestation usually spells death for bedding plants or vegetables.

A plant post-infestation leaves the plant dry, discolored, and leaves wilted as signs of plant stress.

The plant will eventually die if nothing is done against the spider mite infestation.

Plants especially vulnerable to spider mites include vegetables like watermelons, melons, and squash, resulting in smaller yields and sunburning.

More direct damage can be seen on plants like beans and sugar peas and only minimal wear on ornamental plants.

Infestation Symptoms

Plant symptoms or damage of a spider mite infestation are:

  • Tan or whitish-yellow spots on leaves or needles, depending on the plant
  • Sometimes yellowish or bronze discoloration
  • Webbing
  • Distorted leaves and flowers
  • Dusty red or white specks moving around the leaves
  • Random white spots on the leaf
  • An almost sunburned-like complexion

Spider Mites Resistance

The most annoying ability of spider mites is their quick inherited immunity.

Should there be survivors from initial attempts to kill the colony, the next generation will be much more challenging to eradicate.

An example of such is the two-spotted spider mite, a known cannabis specialist who is known to survive many insecticides.

How to Prevent Spider Mites on Your Plants?

After dealing with a spider mite attack, the best action is to ensure it can never happen again.

Spider mites can grow resistant, and maybe still after something in your grow room you unintentionally placed.

So here are several tips for preventing another infestation depending on the location of your grow room:

Indoor Prevention

One of the easiest ways to start an infestation is to accidentally bring it inside with an infected crop.

Remember, even with a small clutch of eggs or a few adult females, you soon have a million spider mites on weed plants, devouring everything.

So it’s important to never move any newly acquired plants or clones from the outside without an initial inspection or quarantine.

The inspection process for every new plant goes as follows:

  1. Use a handheld magnifying glass to search for any potential eggs, bugs resembling specks, holes in the leaf, and other markers.
  2. Dip or spray the plant in a solution of temperature water and soap
  3. Quarantine for at least a week with regular checkups for any appearances of the pests
  4. When entering your grow room, especially from the outside, change your clothes often as pests can hitch a ride on clothing

However, these tips are for only entering and exiting your indoor facilities. Next comes maintenance.

Clean Grow Room

The most crucial anti-pest strategy is to have a safe and clean room!

You can clean out any bugs and keep your growing buds strong by doing the following:

  1. Pick up and dispose of any dead leaves and decaying plant matter away from the indoor garden
  2. Enforce the strict change clothing policy on anyone entering the grow space, especially if they are from another one
  3. No domestic animals are allowed as they both can be potential carriers or simply feed on your crop
  4. Wipe and sterilize everything between enclosures

Maintained Environment

Be sure to regulate the environment and internal temperature into favorable conditions for your plants growing indoors, which is antithetical to spider mite growth and mold

Spider mites love the heat, and keeping the relative humidity between 55-65% can keep your plants free of parasites.

React quickly at the sign of any pests as you closely watch your plants.

The tips go as follows:

  1. Excellent airflow blows away pests, not only spider mites but also fungus gnats and mold.
  2. Maintaining humidity levels and room temperature slows down infestation rates.
  3. Air filters help prevent any outside intruders from entering.
  4. Sprinkle in some diatomaceous earth for good effect.
  5. Bring over seeds rather than clones, as they are less likely to be carriers.
  6. Consider growing your crop hydroponically, as pests are less likely to thrive in a soilless environment.

Outdoor Prevention

Outdoor pest prevention follows many of the same rules indoor prevention follows.

Always wash, inspect, and quarantine any new plants. Also, don’t forget to change clothes as you enter.

Unique outdoor pest prevention goes as follows:

Don’t Remove Beneficial Insects

Whether by biocontrol or just maintaining more natural populations.

It’s best to preserve and care for surprisingly beneficial insects:

  1. Whether it’s ladybugs or the phytoseiulus, their presence is always welcome in warding off pests before any chemical can be used.
  2. Only use pesticides as needed, and it is preferred to use narrow-spectrum pesticides to kill your specific pest problem.
  3. Do not use broad-spectrum pesticides, as the product can kill insects indiscriminately, such as the pest’s natural predators.

Maintain a Healthy Environment

Simply having a healthy garden for your outdoor plants pays dividends for its survival and longevity against invading pests.

  1. Invest in proper ground cover from Diatomaceous Earth to the humble soil cover to act as barriers from anything
  2. Minimize plant stress with humidity and temperature regulation
  3. You can minimize plant stress by providing all the necessary nutrients and water needs.

Frequently Asked Questions

Here are more tips for getting rid of spider mites to protect your weed plants:

What Are the Early Signs of Spider Mites?

Bronze or yellow-colored spots and small holes on the underside of plant leaves are the go-to signs of spider mites

Also, spider mites spin webs around the leaves and stems of your new plants.

You can use a magnifying glass to locate spider mite eggs on either the underside of a cannabis leaf or the webbing itself.

Do Spider Mites Bite Humans?

NO, spider mites are not directly harmful to humans, only plants. A spider mite, however, can still bite and leave irritated skin, swelling, and itching.

Can Spider Mites Live on Humans?

All the spider mites species are herbivorous and thus can’t live on humans. Spider mites not only use plants as food but also as webbing and nest material

Spider mites, however, can latch onto human clothing for transportation to spread their colonies.

How Do You Check For Spider Mites?

You can place a white sheet under your cannabis leaf for a more physical inspection. Next, you shake the plant to have any spider mites fall onto the sheet for observation.

How Do Spider Mites Travel?

Spider mites travel via plants’ proximity and can be shown in the following means:

  • Crawling from one plant to another
  • Latching onto human clothing and shoes
  • Dropping from a higher plant to another
  • Spread from being blown by the win

Why Is Floramite the Last Resort

Floramite is a harsh chemical that is very effective at killing pests but is also very expensive.

However, it can be harmful to humans and animals when ingested, causing an allergic reaction in some people.

If mixed with water, especially in areas with surface water, Floramite is toxic to birds, marine invertebrates, fish, and even bees.


When you try to get rid of spider mites, the task can be, at the best of times, a taxing chore and even a bullet dodged.

Crop destruction by a spider mite infestation is nothing to sneeze at!

Now, you are armed with the knowledge to kill spider mites correctly should you see the signs in your weed garden, indoor or outdoor.