Grow Diaries

Pest control: Catch spider mites early!

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Pest control:  Catch spider mites early!

Imagine you have a healthy little grow going.  You are doing everything right, and all your plants look really healthy.  Your plant may look like this:

One morning you wake up and check your plants and you notice what look like tiny little white specks on a couple of the leaves.  Your leaves may look like this:

Upon closer inspection you notice the specks are actually tiny little holes, like a pin-sized holes. 

You get out your microscope for inspecting trichomes, and you notice tiny little pin sized bugs that may be white, red or brown.  These are spider mites, and up close they look like this:

and this under a microscope:

here is even a little video of them moving around...I promise after watching it you will feel itchy!

What are spider mites and where did they come from?

Spider mites are pests relative to both ticks and spiders.  They feed on cannabis leaves and happen in outdoor grows (often) and indoor grows (far less often).  If  left for too long will colonize and start to develop little webs on your plants. Some outdoor seasons are spider mite free, and others can bring infestations.  Indoors, the spider mites would have come from an outside source.  If you have an indoor grow and used clones, the spider mites could come from the mother plant and garden.  If you used seeds and soil, its harder to say where they came from.  Were you spending time outside?  Were you in another cannabis garden?  Do you have pets?  Make sure you change your clothes before going into your garden and after leaving it.  Definitely change your clothes if you are visiting another garden.  Keep your pets out of your grow room--they might be carrying them in. 

Spider mites lay eggs and multiply quickly.  The takeover can happen in a matter of hours or days, so it is important that you are carefully looking at your plants regularly.  Spider mites are also resilient--when you think they might be dead, they probably aren't.  If a spider mite survives whatever treatment you give your plants, they will lay dormant for a couple days, then come back stronger (resisting your original treatment) creating a superbug.  

How to get rid of spider mites for good

The most important thing is to not panic, but do act with urgency.  If you are catching them in the first couple hours or days AND you are catching them during veg, your otherwise healthy plants will return to normal if you take action now.  It is so key that you caught them early development (and again, even better in veg--during flower getting rid of mites is very difficult).  Especially if you are growing your legal 4 plants or fewer, this is a very controllable situation.  You could segregate affected plants and treat them separately, but realistically these mites are so invasive it is better to assume that if one has them they all do.  After catching issues early, the key to killing all the spider mites is to understand their life cycle.  Your first treatment kills any living mites (but not their eggs).  The second treatment deals with any mites that would have hatched/survived after the first treatment, and you are also trying to keep the mites from laying more eggs.  The third treatment kills everything left.

What you need:

-1 L. spray bottle
-A measuring syringe
-Safer's End All concentrate
-Safer's Insecticide Soap
-Isopropyl Alcohol
-Patience and a positive attitude

Total cost at your local hydroponic store:  $50 or less.

First Treatment:  Kill those mites dead!

1)  Mix 50 ml. of Safer's End All concentrate with 1L. of warm water in a spray bottle, mix thoroughly.  My spray bottle is 1L so it makes mixing really easy.  You can do about 10 plants (give or take) in veg with this much of the mixture.  The mixed spray will keep for about a week, so if you don't use it all, don't worry, you will be spraying again in a couple days.

2)  Water and feed your plants as normal.

3)  Carefully remove any leaves with the spots left by the mites.  Focus on fan leaves (leaves growing directly out of the stem with no flower sites) especially.  Spray these leaves with the mixture and discard.

4)  Spray all leaves on all plants in the grow on both sides, focusing especially on fan leaves and stems.  Also spray the soil, any tools you are using and growing area (you could spray down your whole tent) with the End All mixture.  Be thorough, your plants should be soaking after the application.

5)  Turn off your lights for at least 6 hours after application.  Leaving them on after a spray can burn and damage the leaves.   They need to dry off a bit first.  If you can turn a regular bulb light on in the room so there is some light, great--the plants will just think it is a cloudy day.  Return to your regular light cycle after this.

6)  Continue following steps 1-5 every 3-4 days until you notice no bugs, no eggs, no damaged leaves and everything looks lush.  You could continue this for a couple weeks to be safe. 

Second Treatment:  Kill those super mite zombies!

7)  Once you think you have all mites killed, now it is time to attack the zombie mites that might have survived and spray your plants, soil, tools and grow area with the Insecticide Soap.  Any mites that survived (and maybe got stronger after the first treatment won't survive the second treatment).

8)  Water and feed your plants as normal.

9)  Continue steps 7 and 8 every 3-4 days for 1-2 weeks until you are POSITIVE everything is dead.

Third Treatment:  Triple check everything is dead!

10)  Remove all plants from the grow space and clean space.  Spray walls and floors of room with a mixture of 30% alcohol diluted with 70% water.

11)  Bring plants back into the room and lightly soil, spray top sides and undersides of leaves with diluted alcohol mixture.

12)  Water and feed your plants as normal.

13)  Continue steps 7 and 8 every 3-4 days for 1 week until you are SUPER POSITIVE everything is dead.

A note--make sure that you don't switch to flowering until you have completed steps 1-13.

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