Spider mites or red spider mites are a common nuisance that can be tricky to get rid of. The spider mite bites into individual plant cells and sucks out the contents… leaving tiny speckles of spider mite damage on the leaves. These speckles are easily mistaken for nutrient deficiencies so infestations can often go unchecked. The result of which is a nasty webbing with thousands of creepy-crawlers covering the tops of your plants. Spider mites on plants is a problem but not necessarily a terminal one. This article will ask: what causes spider mites? How do you know if you have spider mites? More importantly, how do you get rid of spider mites?
What are spider mites?
Spider mites are garden pests that reside on the underside of a plant’s leaves. The insects protect themselves from predators by spinning shields out of silk webs. Their eggs, which can hatch in as fast as 3 days, are transparent. Females live for 2 to 4 weeks and can lay up to 20 spider mites eggs each day. They really don’t mess about.
Much like the average Californian, spider mites love heat, low humidity and cannabis plants. They’re mostly drawn to soil-grown plants but have been found in hydro set-ups, too. Spider mites on weed is a problem indoors and out.
Growing no larger than a millimeter, these mites are very hard to spot, especially during the early stages of an infestation. It’s easy to confuse the presence of mites with a nutrient deficiency, as the leaf-spots can look pretty similar. If you want to learn how to deal with an infestation, you need to learn how to spot the tell-tale signs of spider mites.
How do I spot spider mites?
Spider mites affect plants whether grown indoors or outdoors. If not managed early, they can wreak havoc throughout your grow. Here are the most common signs of a spider mite infestation:
- Stippling or formation of tiny spots on leaves
- Small, white, translucent eggs on the bottom of the leaves
- Leaves with small spots turning yellow
- Fine, silky webs on or around the bottom of leaves, branches or buds
- Visible spider mites on the foliage
Spider mites and cannabis
Spider mite control is a common problem for cannabis growers. They are difficult to deal with and tricky to spot, but there are lots of other reasons why spider mites are such a notorious pest.
- They multiply. A single spider mite can produce 100 to 200 eggs.
- Sometimes they come back. Getting rid of spider mites is often laborious and time-consuming, which makes it even more depressing when they reappear days or weeks after getting rid of them.
- They have an appetite for destruction. Spider mites are hungry little beasts and, when left unchecked, will quickly multiply and destroy a plant.
- They spin webs. Spider mites create a fine web that can cover leaves and buds like a blanket. As most experienced growers already know, nobody wants to smoke buds covered in spider webs!
- They adapt. Growers must eradicate spider mites as quickly and as completely as possible. If you only get rid of half the population, the remaining half can adapt to your treatments and build resistance.
Two-spotted spider mites especially favor cannabis plants. This type of pest has shown great resistance to insecticides and is known as “the borg”. Fortunately for you, resistance is NOT futile, there are ways of getting rid of spider mites.
How to kill spider mites?
Spider mites have developed a great fondness for cannabis plants and out of all the pests you’re likely to encounter, these are the most common. Maybe they like marijuana because it helps them with anxiety or stress? Who knows? What you do know is that you need to get rid of them BEFORE they get out of control. Knowing how to kill spider mites is a valuable skill to have!
- Reduce the numbers, halt reproduction. Prune ALL affected leaves before briskly (but carefully) hosing down the plant. Spraying with a mix of 9:1 alcohol:water will kill any remaining mites. You can also try the following essential oils mixed with water: eucalyptus, lemon, rosemary, peppermint or cinnamon. Don’t be shy with the dose but don’t get any on the buds – oils can really affect the finished flavor.
- Use mite predators. These are a fully natural way to solve the issue and you won’t need any additional sprays or treatments. They can be a little costly and you might find shipping a bit slow, but if you can get them, use them. If you have a spider mite problem, hire a spider mite killer!
- Alternate. You can also alternate between the two… spray your lemon, peppermint, whichever mix you have chosen. Wait 48hrs, apply the beneficial mite predators. Then don’t spray again for at least week. Repeat until the infestation has been completely eradicated.
How do I stop spider mites from coming back?
Getting rid of the mites is only half the job, keeping them from returning is just as important. Take these steps and you’ll give yourself the best chance of preventing spider mites from coming back.
- Do not re-use soil from plants that have been infested before.
- Keep everything clean. Your tent, your equipment, even your shears. Change your clothes or even take a shower before entering the grow. Spider mites can be picked up from other cannabis plants and other grow rooms, normal gardens, too.
- Quarantine new plants before bringing to the grow room.
- Maintain an environment hostile to spider mites – low temperature, high humidity.
- Remove and destroy all affected parts of the plant but do not add to your compost.
- Keep the mite predators around. This is like having a standing army. It’s costly but effective.
A good grower will maintain a clean, climate controlled environment. They will inspect their plants regularly and will reduce the chances of introducing pathogens into the grow. Always ask yourself: what can I be doing better? Am I cutting too many corners? Am I giving the cannabis plants the BEST chance to thrive? You will grow with every problem you overcome and with experience comes wisdom. We can’t all be Kyle Kushman, but we can try.
“Even the genius asks questions.”