How To Get Rid Of Spider Mites During Flowering

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Spider mites are common pests that attack a variety of plants, especially during the flowering stage. These pesky mites can cause significant damage to your plants and can be difficult to eliminate. However, there are a number of techniques to prevent and get rid of spider mites, which are outlined in the guide below.

What are spider mites?

Super macro photo of group of Red Spider Mite infestation on vegetable. Insect concept.

Spider mites are small, eight-legged creatures that feed on the sap of plants. They are a prevalent pest in North America and may cause significant damage to crops and plants.

These mites are classified as a form of arachnid, which places them in the same biological class as spiders, ticks, and scorpions. In fact, spider mites are more closely connected to spiders and ticks rather than insects.

As for the moniker of these tiny critters, the term “spider mites” is derived from the fact that the mites in this group weave webs. They are one of the most damaging and significant groups of agricultural crop pests globally.

Furthermore, spider mites can be difficult to see with the naked eye as they are very small, and their coloring can often blend in with that of the plant. Generally, they tend to be red, green, or brown in color and will cause the leaves to look dusty or speckled.

Nevertheless, their presence is easily felt as they suck the juice from plants, leaving behind webbing and damaged foliage; thereby, it is important to keep them under control.

Basic Spider Mites Facts

spider mites plant pests
  • Spider mites are tiny critters that are less than 1mm or 0.04 inches in size and vary in color. They may inflict harm to the plant by sucking out the sap, ultimately destroying the plant.
  • Spider mites are an interesting species because they are arrhenotochous, meaning that the females are diploid and the males are haploid. Additionally, spider mites reproduce and multiply by laying eggs on the underside of leaves. The eggs hatch into spider mite larvae, which then go through two more stages before becoming adults. If left untreated, spider mites can quickly infest an entire garden and cause serious damage to the plants.
  • Interestingly, spider mites create silk webs as a way to hide from their predators.
  • Spider mites are very small pests that feed on the sap of plants as well as suck chlorophyll from the leaves in order to survive. They are known to puncture the leaf surface in order to obtain nourishment. As a result of being bitten by spider mites, the leaves will often have a stippling effect and will eventually lose all of their energy, turning yellow or brown.
  • The growth habitat of spider mites is quite extended, and they can be commonly located on many types of plants, flowers, and trees. These mites thrive in hot, dry environments and can survive in temperatures as low as 27 degrees centigrade. They also prefer humidity levels between 45-65%. Spider mites typically lay their eggs in the flowers of the plant, which can cause serious damage.
  • The growth and multiplication rate is quite high in spider mites. They reproduce very quickly and can rapidly infest a garden or grow a room. Female spider mites lay around 900 to 1800 eggs in their total life span, and baby spider mites get adult and sexually active in 5 to 7 days. An average female spider mite gives around 30 eggs daily. If you observe an infestation, it is important to take action quickly to get rid of them.

Where do spider mites come from?

spider mites webbing

Spider mites are listed among the common plant pests, but they are especially prevalent during the flowering stage. They come from other areas and spread through different channels. Here are some ways that you or others might transfer spider mites onto your plants:

  • One way of introducing spider mites to your garden is by bringing in plants that are already infested.
  • Humans can unintentionally introduce spider mites by bringing them in on old unsterilized equipment, plants, soil, shoes, clothing, hair, or other objects.
  • Pets and other animals can transport spider mites to different locations on their body and clothes.
  • And finally, spider mites can be blown in by the wind or transported through water.
  • Insects and spiders carrying them

It is crucial to be vigilant about spider mite inspections, and if spider mites are discovered on your plants, it is essential to eliminate them promptly.

Fortunately, there are a few things you can do to eliminate as well as prevent them from reaching your cannabis. I have included some of the more effective steps in the following sections.

Signs of spider mites infestation

spider mites on leaf

Spider mites are very small, and they can be difficult to see with the naked eye. However, there are certain indicators that can assist you in determining if you have an infestation:

  • One of the most common is seeing them move around under the leaves.
  • Another easiest way to tell if you have an infestation is by looking for spider mite bites. Their look like small dots on the leaves of your plants.
  • Tiny, circular eggs on the bottom of the leaves are also a sign of infestation.
  • When spider mites attack outdoor plants, their feeding creates yellow, orange, or brown spots on leaves. The bitten parts become white, and the leaves may turn dry and curl.
  • If you see webbing on the plant, that’s another sign of an infestation.

Why Are Spider mites Dangerous?

Spider mites are dangerous to plants because they feed on the plant’s cells. This can kill the plant over time, as it will not be able to get the nutrients it needs from its leaves.

Furthermore, they also puncture the leaves of plants and feed on the sap, leaving small yellow or brownish spots surrounded by a yellowing leaf. They also leave behind webbing, which further compromises the health of the plant.

The damage caused by spider mites can stunt the growth of plants, reduce yields, and makes them weak and susceptible to disease, eventually leading to their death.

Let us examine and comprehend in-depth the harm inflicted by these annoying creatures in the next section.

Damage caused by Spider mites

webbing on plant

As you know now, spider mites are pesky critters that can cause significant damage to plants. In addition to their general impact on plants, spider mites attack particular plant parts and a variety of plants, such as:

Spider mites damage weed

Spider mites wreak havoc on weeds as they penetrate leaf cells in order to scavenge nutrients. The weakening leaves begin to have an impact on the whole plant. As the herbs fight to share their nutrients with the mites, their growth slows.

The crop droops, and it is difficult for the buds to reach their full size and maturity. The plant may perish if left untreated owing to its extended deterioration.

Spider mites on leaves

Spider mites can cause severe damage to leaves.

They typically enter the plant through the leaves and begin to feed on the chlorophyll, which eventually leads to the death of the leaf. Moreover, by sucking the life out of leaves, they can cause extensive damage that can lead to reduced yields and even plant death.

Spider mites sapping on leaves may result in dark holes where the sap and nutrients have leaked out, yellowing and stippling of the leaf surface, or may cause the leaves to curl.

If left untreated, they can quickly damage a plant, so it’s important to get rid of them as soon as you notice them.

Spider Mites and Flowering

Spider mites can be a big problem during the flowering stage of growth. They can cause buds to stop maturing and can even lead to the loss of the entire crop. It is essential to watch out for spider mites and take immediate action if they are spotted.

In fact, there are several ways to get rid of spider mites; discover some successful spider mite elimination methods in the following section.

How to Get Rid of Spider Mites During Flowering

Spider mite infestation on a hedge in the garden

Spider mites are a type of bug that feeds on plant juices. Spider mites reproduce quickly, and if left unchecked, the mites will cause damage to the plant.

Nevertheless, as I mentioned before, there are techniques that can be used to eliminate these destructive pests and save your crop, especially during flowering.

In fact, in this section, I will elaborate on each method individually: 

Prune and Manual Pick

Spider mites can be a big problem (especially during the flowering of plants), as they can quickly damage the flowers and buds. And while there are many ways to eliminate spider mites, two methods that seem to be most effective are pruning and manual picking.

Pruning involves removing the infected parts of the plant; you can cut off all the infected branches and leaves and then dispose of them properly.

Manual picking, on the other hand, is simply plucking the spider mites off of the plant with your fingers.

Moreover, pruning helps the plant to conserve its resources. By removing the dead or damaged parts of the plant, you are helping the plant to focus its energy on healthy growth.

That said, I would like to mention here that though both these methods are quite effective, they are more hands-on approaches and may not work for severe infestations.

Carbon dioxide Gas

Spider mites are common pests for indoor and outdoor plants. They can be difficult to get rid of, but the use of Carbon dioxide gas is an effective way to get rid of them.

In fact, carbon dioxide gas is safe to use, and it’s a fast and easy way to get rid of spider mites. It is a non-toxic, environmentally friendly as well as a cost-effective technique, making it an excellent choice for anyone looking forward to eradicating these pests.

However, to incorporate this method, you will need the following equipment:

  • A CO2 Gas Cylinder along with a regulator.
  • A Vacuum Cleaner.
  • A Meter to measure the pressure of the gas.
  • Brushes to clean the plants.


Step 1: Set the gas meter at 11,000-12,000 ppm in an adequately enclosed growth space. However, 16,000 ppm is OK if the plants are housed in a tent. This is to compensate for the gas waste. If the pressure pump is unable to provide a greater pressure, it is preferable to use a ppm calculator to calculate the optimum pressure.

Step 2: Next, determine the necessary quantity of gas for your growing area. For proper computation, you can access the online calculators.

Step 3: After making all the necessary preparations, turn on the generator. High concentrations and pressures of carbon dioxide may result in suffocation and death. Therefore, it is essential to evacuate the area immediately after turning on the generator.

Once the requisite pressure is achieved, the generator should be turned off. Before entering the room, don’t forget to turn on the exhaust fans for about one hour to eliminate the gas. This is necessary to prevent carbon dioxide poisoning.

Step 4: Finally, vacuum the plants. Since you don’t want to kill the plant with the vacuum pressure, be sure to utilize it at an appropriate intensity.

Additionally, you may use paintbrushes to wipe the leaves in an upward orientation. This will eliminate all insects, insect eggs, and spider webs.

Remember that the carbon dioxide gas procedure must be repeated within the following five days in order to ensure thorough cleansing and better thereby better results.

Essential Oils

Essential oils offer an organic and non-toxic way to get rid of spider mites during flowering.

There are a variety of essential oils (such as marigold, neem, peppermint, or rosemary oil) that can be used, each with its own unique properties.

Moreover, the essential oils will kill the spider mites while being gentle on your plants.

Knockdown & Chemical Control 

There are a few different ways to deal with spider mites when they’re present in large numbers. One is to use knockdown products that will kill the mites on contact. These include neem oil, pyrethrins, azadirachtin, and horticultural oil.

Another option is to use chemical controls such as miticides, which will also kill the mites on contact; however, miticides should be used as a last resort.


predator lacewings

While there are many commercially available miticides, predators offer an organic and biological option that can be very effective in controlling spider mites.

In fact, predators are beneficial insects that will eat the spider mites, helping you to get rid of mites permanently. There are a number of predators that can be used, including ladybugs, lacewings, and parasitic wasps.

However, it is important to introduce these predators into your garden early on before the spider mite population has had a chance to grow out of control.

Alcohol Solution Wash

To kill spider mites during flowering, you can use a 1:9 mixture of isopropyl alcohol and water. This mixture will clean the spider mites and their eggs, preventing them from reproducing and causing further damage to your plants.

You can hose down the plant with this alcohol solution.

However, make sure to use a showerhead that produces a gentle spray so you don’t destroy the leaves and flowers. 

More importantly, pay special attention to the undersides of the leaves, as that is where the bugs and eggs are typically resident.

Prevention is always mightier than cure!

prevent spider mites on leaf

Prevention is always mightier than cure, and this is especially true when it comes to spider mites. There are a few things you can do to prevent spider mites from invading your plants, including:

Install air filtration systems

Installing an air filtration system is a great way to stop spider mites from getting into your grow room. The system will filter out any bugs or pests that may be in the air, preventing them from reaching your plants.

Remember to clean the vents on a regular basis in order to ensure that the system is working properly.

Practice extreme cleanliness

There are a few things you can do to incorporate cleanliness around your plants and thereby prevent the invasion of spider mites.

First, keep your grow room clean and free of any debris. This will make it difficult for the mites to find a place to live.

Second, sterilize all old equipment before using it in your grow room. And finally, practice extreme cleanliness by washing your hands often and keeping your work area clean.

Maintain low temperatures and high humidity

To prevent spider mites infestation, you need to maintain low temperatures and high humidity levels. This will make it difficult for the spider mites to survive and will help get rid of them.

Quarantine new plants

Another effective way to prevent spider mites is to quarantine any new plants from the rest of your garden until you are sure that they are free of spider mites.

Don’t remove the predatory insects.

As you already know, predatory insects are quite beneficial as they feed on any spider mites left behind, thus preventing them from harming your plants.

Therefore, do not remove these predators from your garden; they are an important part of the ecosystem.


Spider mites, the pesky critters invading healthy plants, can be a major problem for weed growers, especially during the flowering stage. They may spread rapidly from plant to plant and inflict considerable harm. However, you may use any of the above-mentioned techniques to get rid of these pesky critters.

About the author

A biotechnologist by profession and a passionate pest researcher. I have been one of those people who used to run away from cockroaches and rats due to their pesky features, but then we all get that turn in life when we have to face something.