Spider Mites on Buds at Time of Harvest – What to Do?

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One of the biggest fears any growers has is discovering spider mites on their buds right before harvest time. This is especially disturbing when you notice the invasion right before harvesting or drying.

To top it off, an infestation of spider mites needs to be dealt with immediately. In truth, prevention is the best way to deal with spider mites.

However, sometimes they can go unnoticed until the eggs hatch and multiply. Once they are discovered , it is vitally important that you eliminate the spider mites quickly before they destroy your whole crop.

What are Spider Mites?

Oftentimes, many experienced growers will discover they have spider mites when viewing trichomes with a loupe or microscope. However, you don’t need special equipment to discover that you have an infestation of this devastating pest.

Actually, spider mites are pretty easy to identify, especially if the eggs have hatched . As it happens, this pesky bug can reproduce at aa very fast rate.

Frankly, just one spider mite can lay 100 eggs during a course of 2-3 week period. Spider mites are not insects but are in the arachnid family.

They are actually related to scorpions and ticks. The dreaded pest lives in colonies and often forms a web, depending on the type. The most common is the red spider mite.

Closeup picture of mite on the yellow clothes isolated

Other types of spider mites include Pacific, tumid, and Spruce (mostly invades trees).

As mentioned, the spider mite reproduces rather quickly. Typically, one spider mite will produce 100 eggs in its lifespan, which is about 30 days.

Eggs are usually laid underneath the leaves and can easily go unnoticed. In addition, the eggs generally hatch within 3 days and these same babies become sexually mature at 5 days.

In other words, the newborns can breed when they are just 5 days old. Because of the accelerated reproductive rate, the spider mites colony adapts very quickly and easily resists pesticides.

Red Velvet Mites, Rain Bugs, Trombidiidae

Spider mites are like leeches, they literally suck the juice out of plant leaves. At first, the leaves have tine spots which are hard to detect. Later, the leaves become discolored and yellow.

At the later stages of infestation, the leaves fall off and your plants buds become worthless. At this point, it is almost too late to harvest the top half of your cannabis plant.

How to Identify Spider Mites

Because spider mites are so tiny, their presence is seldom seen until they have multiplied and done a lot of damage. In truth, spider mites are nearly invisible to the naked eye.

These small creatures are only.4 mm or .02 inch in size, that’s about the size of a speck of dust. In order to identify a spider mite correctly, you need a 10x hand lens.

Generally the underside of a leaf is inspected. Fortunately, if you can detect spider mites at an early stage of their growth cycle, they can easily be controlled.

Cannabis leaf with water droplets

If you don’t have the time to look for spider mites or the equipment to microscopically inspect your plants, then there are signs that you can look for

  • The plants growth is stunted
  • Leaves have visible signs of discoloration
  • Leaves develop yellow spots on the underside
  • The underside of the leaves may turn brown or white
  • The fruit or buds can sometimes be smaller or they are deformed
  • There are webs on the leaves and stems that look similar to a spider web
  • Leaves are yellowing and dying without an explanation like over-watering or aging
  • There’s accumulation of dust-like material on the bottom or top of the leaves. Hold a piece of white paper underneath the leaf, tap – if specks fall then they are probably spider mites

Note: Spider mites try to avoid contact with the extra sticky trichomes. However, they can easily encircle a whole fan leaf or a full bud with their webbing.

How to Prevent Spider Mites?

Prevention is one of the best ways to avoid spider mite infestation or at least massive damage to your plants. Fortunately, prevention is an easy and simple method.

In fact, most of the preventative steps you need to follow are based on common sense. Keep in mind that many of the preventative measure can be time consuming.

Marijuana and Cannabis growing indoor

However, basic preventative steps are well worth the time and could actually save your plants from spider mite infestation.

  • Proper Grow Room Settings – spider mites generally appear when everything is dry. To discourage them from breading, place your plants in a controlled environment where they have optimum humidity, temperature, and proper watering.
  • Inspect Your Plants Often – it is imperative that you inspect your plants on a regular basis. Simply look at both sides of your cannabis l leaves for signs of damage.
  • Switch to Hydroponics – spider mites do very well in an outdoor environment. In fact, spider mites flourish in the outdoors where soil is used as a medium. Although, they can also appear in a hydroponic setting , the risk of getting spider mites is much lower.
  • Keep the Grow Area Clean – by keeping the grow area clean you drastically reduce the chances of infestation. Likewise, it also helps prevent molds, and other issues.
  • Reduce Cross Contamination – never place any of your outdoor plants into the grow room. Oftentimes outdoor plants re infested with spider mites. If you have no alternatives, make sure that the outdoor plant has a separate area from the other plants for at least two weeks.

How To Get Rid of Spider Mites

When you first discover that you have spider mites, you want to act quickly and accordingly. Spider mites are renowned to breed quite rapaciously.

In fact, many experts agree that you should always have the necessary products and tools on hand just in case you have an infestation. There are numerous ways to get rid of spider mites to help save your plants and your bud.


  • Vacuum – use a handheld vacuum on low power , gently suck the mires off of your plants
  • Pruning – physically removing the spider mites from the leaves. Prune and clip off all infested leaves.
  • Water Spray – use a hose with a somewhat forceful spray to remove the mites from your plants. You can also attach a multi-hose sprayer with soapy water and use it to spray your plants.
  • Lady Bugs – ladybugs love spider mites. In fact, many claim it is their favorite food. Lady bugs can be found at some nurseries and online. Ladybugs may not be best for outdoor growing because they can easily fly off. However, they are great for grow rooms and greenhouses.
  • Neem Oilneem oil is a natural and organic pesticide that not only kills spider mites but prevents recurring infestation

With Insecticides (as a last resort)

Using insecticides should be your last resort to getting rid of spider mites. You should always try using more natural and preventative measure first.

Today there are several commercial insecticides available on the market such as 3 in 1, Boiadvanced, Ortho, and many others.

Spider Mite FAQs

Can I Smoke Weed With Spider Mites In It?

Although there is no scientific evidence that smoking mite infested weed is harmful, it’s probably not a good idea. For one, the weed may have been sprayed with insecticides or soapy water to get rid of the spider mites.

Additionally, the taste is not going to be that great.

What are the Side Effects of Smoking Spider Mites?

Unfortunately, there has not been a lot of scientific research on the side effects of smoking spider mites. Frankly, in order to test the side effect, there would have to be numerous people who volunteered to smoke spider mite infested weed for an extended amount of time.

Hand holding a cannabis joint against trail

Because of the smoke involved, it is safe to assume that it could cause lung, throat, and breathing issues.

What are the Side Effects of Smoking Spider Mites?

Unfortunately, there has not been a lot of scientific research on the side effects of smoking spider mites. Frankly, in order to test the side effect, there would have to be numerous people who volunteered to smoke spider mite infested weed for an extended amount of time.

Because of the smoke involved, it is safe to assume that it could cause lung, throat, and breathing issues.

Last Thoughts

Although, getting rid of spider mites is a huge challenge, prevention is quite simple and easy. If you remember the basic preventative measures, then you should have minimal issues with these horrific pests – keep grow area clean, inspect leaves with a good lens, keep outdoor plant away from indoor plants, and optimal greenhouse conditions.

Again, if you discover you have spider mites, remedy the issue as soon as possible.