how to kill spider mites on pot plants

Cannabis 101: Ladybugs as a Natural Solution to Spider Mites

Are your plants looking a little worse for wear? Spider mites could be at the root of the problem. Learn how to combat an infestation using one of the cannabis grower’s most unsuspecting allies: ladybugs!

Humans have used the cannabis plant for thousands of years as a source of food, fibre, and psychoactive recreation—we still do to this day! But we’re not the only species that enjoys the herb. Myriad creatures, both great and small, rely on the cannabis plant for shelter and sustenance.

Of all the cannabis-chomping critters you’ll encounter in your garden, spider mites will likely be one of the most common. Although small and seemingly harmless, these minute menaces can cause some serious damage to your crop.

Yet, hope is not lost. Just as some species are menaces, others are saviours. Could ladybugs be the answer to a spider mite plight?

What Are Spider Mites?

Small, colourful, and many-legged; spider mites aren’t actually insects. They are a type of arachnid closely related to spiders and ticks. They possess two traits that place them in this taxonomic category: two main body parts and eight legs. More specifically, they belong to the Tetranychidae family, which includes around 1,200 other species.

Irritating, creepy, maybe even cute to some. Spider mites might be a lot of things, but there’s one thing they certainly are not: fussy eaters. These creatures like to hang out on deciduous trees, evergreens, and a variety of annual plants. They’ll snack on just about all of them.

Although they appear to love the taste of cannabis tissue, they are also prolific grazers of blueberry, strawberry, and cucumber plants, as well as snap beans, peas, tomatoes, and lettuce. Spider mites will even have a go at your flower beds—marigolds and violas not excluded.

Spider mites start off as eggs, enduring the cold and harsh winter, then hatching when temperatures begin to rise. They emerge as dark-coloured larvae and swiftly morph into pupae before maturing into their final form.

It doesn’t take long for a new colony to prosper, especially when temperatures are warm. They congregate on the underside of leaves, including those large fan-like ones on your cannabis plants, where they string up webbing over the affected tissue—hence the name “spider” mite.

Will Spider Mites Kill My Cannabis Plants?

Yes. Spiders mites can cause real damage to cannabis plants. If an infestation sets in, expect damage to range from stunted growth all the way to fatal destruction. These small creatures possess sharp mouthparts that pierce cannabis tissue and suck out chlorophyll. After feeding on the underside of a cannabis leaf, they leave behind small spots. Eventually, leaves will become yellow, discoloured, and distorted.

Cannabis plants rely on their fan leaves and their internal chlorophyll to photosynthesise and create energy. If the damage becomes severe, they may lose the ability to carry out this key function. This will slow down growth and impact yields. Eventually, if the problem remains unaddressed, plants will die.

How to Spot and Identify Spider Mites

You might struggle to spot these little guys with the naked eye, seeing as they’re usually less than 1mm in size. After whipping out a magnifying glass and taking a closer look, you’ll notice their white legs and diversity in colour. Some are red, whereas some are yellow and others orange.

However, you’ll usually notice signs of their presence before you directly lay eyes on a specimen. Other symptoms will only appear after a large and obvious infestation has gained a foothold. The key signs that indicate a spider mite infestation include:

  • Interwoven web-like threads that dominate the underside of plants
  • Small white or yellow spots (feeding damage)
  • Wilting and distorted leaves
  • Yellowing and discolouration of plant tissue
  • Stunted or slowed growth
  • Dead or dying plants

Of course, physically seeing a spider mite provides the most striking evidence that you’re dealing with the pest species. But can you tell them apart from other species? Look for these characteristics:

  • Two main body parts
  • Eight legs
  • Red, yellow, or orange in appearance
  • Around 1mm in size
  • Two dark spots, one on either side of the body

Now that you know what you’re dealing with, let’s explore several natural ways of addressing the invasive issue at hand.

Are Ladybugs Good for Dealing With Spider Mites

Fortunately, not all insects have a desire to munch on your cannabis plants. In fact, some of them are far too busy snacking on other insects to even consider it. These beneficial predatory insects are an important ally to cannabis growers, and every cultivator should welcome them into their garden.

Ladybugs are among the most effective predatory insects. These brightly coloured, spotted insects might look innocent; but don’t be fooled. Ladybugs are voracious killing machines. They don’t employ a specialised trapping technique or stalking method; they simply walk right up to their prey and start feasting.

Ladybugs love to munch on spider mites, so much so that they know how to track them down. They are attracted to the smell of these creatures, as well as to the leaf damage typical of a spider mite infestation. After locating a herd of spider mites, ladybugs get to work. A single ladybug will consume around nine mites per hour, equalling up to 100 mites in a single day. And that’s just one ladybug!

Are Ladybugs a Danger to Cannabis Plants?

No. Ladybugs won’t do any damage to your cannabis plants—they are strictly carnivores. When they’re not taking out spider mites, they’re munching on other pests and laying their eggs in the colonies of invasive insects.

Novice gardeners have a tendency to worry when seeing any form of insect patrolling their garden. But fear not! Some of these creatures are vital allies that work to keep your plants healthy, protected, and productive.

How to Use Ladybugs to Control Spider Mites and Other Pests

Releasing some ladybugs into your garden serves as a swift and effective means of dealing with a spider mite invasion. Most garden centres and nurseries sell ladybugs that are ready to be released around your cannabis plants. Follow the tips below to make sure your population gets comfortable in their new home:

  • Employ large quantities: Although a single ladybug can remove a huge amount of spider mites, you’ll need to release many of them all at once to get the job done. Spider mites become established fast, and some of the ladybugs may die or fly away.
  • Release during early morning or early evening: Ladybugs aren’t fans of the heat. If you release them during the heat of the day, chances are they’ll fly away to find shelter. Releasing them at the right time will increase the chances of them sticking around.
  • Spray your plants with a light mist: Cover your plants in a coat of moisture to encourage the beneficial critters to feel comfortable and stick around.

Building Your Own Ladybug Hotel

Building a ladybug hotel will provide a shelter full of nooks and crannies that ladybugs will feel safe and protected in. This structure will encourage the insects to stick around, and will also tempt wild ladybugs to enter and remain in the garden.

Essentially a messy labyrinth made from natural materials, ladybug hotels are super easy to make. They can take any shape you please, from more sophisticated house-like structures to bags stuffed with pine cones or wooden pallets loaded with straw.

Use the following materials lying around in your shed, garden, or kitchen to make your own ladybug hotel [1] :

  • Straw or hay
  • Lollipop sticks
  • Chicken wire
  • Rope
  • Pine cones
  • Bricks
  • Plant pots
  • Crates

Other Ways to Deal With a Spider Mite Infestation

Although ladybugs are effective at reducing spider mite populations, there are other preventative and curative measures that growers can employ. Explore further options below.

Neem Oil

As a natural pesticide, neem oil helps to repel various species of pests—including spider mites—without the use of dangerous synthetic chemicals. Blast the underside of affected leaves with a neem foliar spray to force spider mites out and blow off their webs.

Add one teaspoon of neem oil per litre of warm water. Add 4–5 drops of surfactant, add to a spray bottle, and apply.

Spider mites belong to a long list of insects that like to feast on weed plants. Learn more about them here, and how to use labybugs to end their invasion.

5 Ways to Get Rid of Spider Mites during Flowering

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5 Ways to Get Rid of Spider Mites during Flowering

Whether you choose to grow cannabis outdoors or indoors, in soil or hydroponically, for your own personal use or commercially, any rewards to come at harvest time are well-balanced with a long list of risks along the way.

By the time your plants reach the flowering stage of their growth, when the buds begin to form and fill out, you are likely heavily invested in time and money to get them there and seeing them through safely to harvest day is among your highest priorities. During this phase, you want all of the plant’s energy going into feeding those bulging colas and swollen trichomes.

With an intimate daily relationship with your garden, farm, or grow, there are certain tell-tale signs that can express a plant’s health at a glance to help you determine if there is a potential problem that needs attention. Sometimes these signs point to a nutrient deficiency or airflow problem, often easily remedied. Other times they point to something more sinister, and that is the case with the resilient spider mite.

The spider mite is a microscopic 8-legged arachnid that enjoys life in gardens, whether they are growing cannabis or vegetables. As their name implies, they do spin webs that they use to protect their eggs and new offspring.

A female spider mite can lay over 1,400 eggs per year. Each egg hatches in three days and the resulting offspring is fully mature and ready to reproduce in just five days. This rapid and compounding population growth poses a serious risk to any gardener, farmer, or grower who hopes to eradicate the crop-threatening pest.

Spider mites puncture the surface of cannabis plant leaves to feed on the plant’s life-giving chlorophyll found in the cells within. Well into their infestation, the initial visible sign of their repeated feeding is a whitish or yellowish speckled or mottled effect called ‘stippling’ on the fan leaves of the plant.

Since the mites are so small, and their eggs even smaller, and both tend to reside on the underside of leaves, this discoloration of the foliage is often your first indicator that something is awry.

If left unchecked, the multiplication of numbers begins and you may see entire fan leaves curl up and drop from the plant once sucked dry by the mites. This is also when you’ll begin to notice the web-spinning as mature mites migrate from one leaf to the next, leaving behind fine white wisps of webbing as evidence of their infiltration.

Though they do try to avoid contact with the ultra-sticky trichomes that are hopefully beginning to blanket your buds by this point, spider mites can envelop an entire fan leaf or even a full bud in their webbing.

As you can imagine, you wouldn’t be too keen on smoking such a bud, and nobody will be interested in buying it either, so what can you do to get rid of spider mites during flowering?


You’re heard the expression “fight fire with fire”, well one good way to deal with spider mites is to fight bugs with bugs.

There are many predatory insects that can be introduced to your grow environment that will ignore your prized pot plants and instead immediately go to work feasting on your 8-legged unwelcome guests.

Ladybugs are voracious mite murderers and a cannabis grower’s best friend for an all-natural pest solution.

The most common spider mite affecting cannabis grows is the “Two Spotted Spider Mite”. Aside from ladybugs, there are other types of mites, thrips, and bugs that also love to munch on your enemy, but will leave your plants alone.

In outdoor cannabis grows, these predator bugs will feed until the food (spider mites) is gone, at which point they fly off.

This solution is best used when mite populations are still low.


By pruning, we don’t just mean clipping leaves – though we will get to that – but also physically removing the mites themselves from the plants by hand or with a very low powered vacuum tube.

If removed by hand, they need to be squished. Gross, yes, but no mercy for these intruders. If removed by vacuum, you need to get the contents of the vacuum into a sealable bag and into a trash can far, far away from your grow.

Again, these spider mites can be very hard to see with the naked eye and their eggs even more so. So this hand-pruning method is also best employed early in the infestation when numbers are low. Even then, expect to repeat the process for several consecutive days to effectively eliminate the problem.

Since mites thrive in warm, stagnant environments, try dropping the temperature if possible and increasing airflow to slow their reproduction as you squish away.

For the leaves themselves, if the leaf is showing obvious signs of distress and has 50% or more of its surface affected by mite feeding, it’s probably best to snip it off and allow the plant to focus its resources elsewhere.


If you’ve tried the methods above, or have just discovered a disturbing colony of spider mites, you can try hosing the plant(s) off with a gentle showerhead and regular water which can physically flush the mites and webs off of the plants.

Note that this will not kill them and they may scatter. This water shower also will not budge the eggs that are usually pretty firmly attached.

For a stronger solution, simple isopropyl alcohol can be mixed at a 1:9 ratio with regular water and applied with a garden sprayer. This will kill most mites on contact without harming the plant, but you definitely want to try to avoid spraying the buds with alcohol if you can avoid it.

Whichever method you try, remember to thoroughly wash the underside of the leaves, as that is where spider mites and their eggs tend to dwell.


Many cannabis farmers have reported success in the war on spider mites by using varying concoctions of different essential oils extracted from plants like peppermint, rosemary, cinnamon, eucalyptus, and more.

These oils are diluted with water and applied to your plant’s affected leaves with a garden sprayer or spray bottle. You’ll once again want to avoid coating your buds with this aromatic mixture, especially so close to harvest.

One of the most popular essential oils is Neem Oil. Though most won’t admit it, Neem Oil usually has a permanent place in a grower’s toolkit, and when used sparingly, can be a highly effective weapon when fighting mites. When this foul-smelling product is used incorrectly, you can ruin your plant or crop while trying to save it.


When all else has failed and your crop is on the line, there are dozens of commercial pesticides on the market that specifically target spider mites and do so very effectively.

Unfortunately, a significant number of these products are not intended for use on goods that are intended to be lit on fire and inhaled and so should be avoided completely.

The closer the crop gets to its harvest date, the harder it gets to properly flush these products from the plant or to avoid affecting the buds with these invasive measures.

Organic or otherwise, insecticidal soaps, solutions, and strips absolutely work, but they are rarely made from stuff that you want to breathe, smoke, or eat so treat them as a last resort.

Sometimes the infestation is so bad that an entire plant or harvest is lost to it. If it was an indoor grow, the entire growing environment needs to be methodically cleaned top to bottom with a bleach /water solution.

Any new plants or clones that come into the grow site need to be quarantined for at least a week before joining the rest of the garden to ensure that they are not carrying any near-invisible pests with them.

Mites and other invaders are often introduced to your grow by hitching a ride on you! So a shower and a change of clothes before entering your indoor garden is always a good idea. Keeping random friends and guests away is prudent as well. They can help you come trim later.

A sprinkle of diatomaceous earth around your pots, atop your soil bed, across your door thresholds, and at the ends of your dry-lines will shred and dehydrate mites that try to cross it and will not affect your plants.

The best way to fight mites is before the battle begins.

An ounce of prevention up front can lead to pounds of high-yielding cannabis at the end, and fewer headaches for you, the grower, along the way.

5 Ways to Get Rid of Spider Mites during Flowering Share & Bookmarking Advertisement 5 Ways to Get Rid of Spider Mites during Flowering Whether you choose to grow cannabis outdoors or