Posted on by Alex Thornton

Pests - Spider Mites on lemon tree

Spider mites are little Acari mites that are smaller than 1mm in size and vary in a range of colours. Spider mites are a part of the Tetranychidae family which includes over 1000 species.

There are many different mites but only a few are common to specific plants including, two spotted mite, hemp russet mite, broad mite, black spotted mites, red spotted mites and oriental mite.

Spider mites mainly sit on the underside of the leaf making them very hard to notice until the infestation is bad enough that the mites have spread all over the plant, making them clearly visible from a small distance to the human eye.

If your plant appears to be suffering for unknown reasons, inspect your plants thoroughly to ensure there isn't an infestation of these mites, as most people overlook this.

Spider mites thrive in warm conditions (preferably around 27°C), which is why they are more common indoors, searching for an ideal environment to breed and live in.

A female spider mite can live for approximately 3-4 weeks, laying up to 20 eggs per day once sexually mature (they are sexually mature from 3-5 days old!)

A single female spider mite can lay close to 500 eggs in her life cycle.

The eggs are transparent and minuscule and will hatch within 3 days, they have a hard outer shell to protect the eggs from attack.

So basically, if spider mites are not noticed within a couple of days after noticing health problems they can take over your grow room within a week easily, as the mites have an ability to down-regulate the immune response of a plant, although some studies have shown that the application of Harpin Alpha Beta protein may help reduce the immune response effect on the plant.

Spider Mites pests

To get rid of these nasty little pests, I like to make up an organic spray to try deter/kill them from the growing area.

What you will need:


Crush your garlic clove as small as possible and add into your 1L of water.

Add teaspoon of dishwashing liquid.

Add Pyrethrum and Mite-Rid in dosage rates on the bottle.

Add contents into 1L spray bottle.

Once you have made the spray, mist the undersides of the leaves until saturated. You want to do this at least 2 times per day once in the morning and once at night, ensuring your ventilation system (if you have one) is switched off, the idea is to permeate the room.

Keep spraying for around 5 days this should interrupt the spider mite’s life cycle and hopefully rid your plants of these pests!

Written by Alex Thornton