If you’ve spent weeks germinating seeds and bringing up your plants, nothing ever quite this as hard as a sudden and persistent pest problem. One of the most frustrating is know how to get rid of white mites, a close cousin to red spider mites, and one that is much harder to detect.
If it seems like an insurmountable hill to climb, don’t worry. We’ve got you. White mites are treatable, preventable, and with some fast action you can turn things around and still get a good crop. So let’s look at how to get rid of white mites.
All About White Mites
White mites are a miniscule arachnid, closely related to red spider mites, and a subspecies of the two-spotted spider mite (Tetranychus urticae). The larger females measure 0.4mm long, and the males 0.2-0.3mm, with round bodies and eight short legs.
They feed on plants and decaying plant material, with a life cycle that repeats whenever the temperature is between 10°C and 35°C, hibernating in a state of complete dormancy through winter as adults.
Identifying White Mites
White mites are hard to spot, thanks to their diminutive size, but are visible to the naked eye as small white dots, about the size of a grain of sand.
Up close, or through a microscope, they have round bodies, and females have two spots on either side of their bodies. Larvae, nymphs and adult white mites have eight legs, and small mouth parts which can easily pierce the surface of a leaf.
Where to Find White Mites on Plants
White mites congregate and feed on the underside of leaves, commonly on houseplants and annual or herbaceous plants. Tomatoes and brassicas tend to suffer more regularly than other plants in the veg garden.
The easiest way to spot them is when they’ve laid a large number of eggs. Like most species of arachnid, they produce a silky web, but rather than using it to catch prey, these herbivorous mites use it to protect their eggs.
White Mites’ Life Cycle
White mites have, at most, a three week life span during their active season, but can live dormant in the soil through freezing winters.
Their active lifecycle starts as an egg (barely perceptible to the naked eye), and they emerge as larvae. The larvae develop into nymphs which shed their skins as they grow into full-sized adult white mites.
The whole process takes around four to five days, and the adults live for a further two weeks. Each female white mite can lay up to 70 eggs in her lifetime.
White Mites’ Habitat
There is no set native habitat for white mites as they thrive in all corners of the earth, on any soil type and any plant species they can safely feed on.
White mites, much like red spider mites, thrive in dry conditions, and on plants that are well fed. Houseplants and vegetables are incredibly popular food sources and habitats for white mites because we tend to care for them in this way, with liquid fertilisers during the growing season, and short, frequent watering.
How Do White Mites Damage Plants?
White mites feed on sap, which is most accessible through the xylem and phloem cells around the midrib or veins on the undersides of leaves. These cells contain nutrients, sugars and chlorophyll, providing a growing white mite with everything it needs to thrive.
Signs of White Mite Damage
Early signs of white mite damage to leaves are minute brown spots on the underside of a leaf, where it has healed over a bite. If infection takes in the bite wound, the leaf will develop rusty spots that grow and develop until they are visible on the surface of the leaf as well as underneath.
As infection spreads, it can take many forms, but any patchy discolouration should be removed to prevent infections passing back down into the stem, whether rusty, black, brown, yellow, or a target-shaped combination of colours.
How to Prevent White Mites
Preventing white mites, and the resulting damage takes a combination of efforts:
- Maintain moist soil
- Feed, but don’t overfeed your plants
- Enable natural predation
- Plant scented herbs
White mites love dry soil and well-fed plants. Houseplants are incredibly prone to white mites for just that reason. Our vegetables tend to end up in a similar state in mid-summer too.
With regular liquid fertilisers and not enough attention paid to watering, white mites have the ideal conditions to thrive.
Creating the Conditions to Prevent White Mites
However, regardless of what summer might throw at you, there are still ways you can prevent white mites organically, and naturally, and that will benefit your garden more widely too.
Plants that white mites hate
Firstly, plant things that white mites hate. Peppermint is actively toxic to white mites, and heavily scented herbs like rosemary, basil, and lavender are great plants for deterring white mites, even in dry soils.
Indoors, and around houseplants, drop peppermint essential oil onto the rims of pots to deter white mites and other pests. Or, plant kitchen herbs like basil in pots for window sills around the house – not just the kitchen.
Keeping a tidy home and garden will limit white mites
White mites can live on fallen leaves, dried oats, grains, and even partially rotten vegetation. Indoors, preventing this sort of accidental white mite habitat is as easy as hoovering.
In the garden, it’s about finding balance. White mites like mulch, particularly leaf litter, as the surface stays dry but locks moisture underneath. That makes healthy plants, with dry surface compost around the base. So avoid mulching in spring or summer, and rake up fallen leaves.
Promoting biodiversity and white mite predators
Through winter, being a little bit lazy can actually be good in the garden. Leaving dead stems to die back naturally, and allowing fallen leaves, or mulches to stay in place provides a habitat for predators.
While this won’t actively remove white mites (and can offer them a safe haven for winter) it will support populations of ladybirds, beetles, small wasps, and other insects that feast on white mites and their larvae come spring.
How to Get Rid of White Mites
Once white mites are present on a plant, there are some great solutions to get rid of them quickly, and a few longer-term methods that will support your garden health more widely, and prevent recurrence.
As with everything in gardening, proper treatment requires a few different tricks at the same time.
Caring for Plants to Treat White Mites
Once white mites are present on a plant it’s still possible to care for your plants in a way that reduces their spread.
Water more often, and more generously for a few weeks, and reduce feeding. Your plants might not enjoy the short-term treatment, but it will affect how well white mites can sustain a population.
Organic White Mite Treatments
Neem oil is probably the most famous organic treatment for houseplants and vegetable pests. It works by initially disrupting their nervous system and the coating it leaves behind is so distasteful that they stop feeding altogether.
Neem is an indiscriminate killer though, and will kill pollinators and beneficial insects too, so use it with care outdoors.
In the same vein as neem, pyrethrum, the chemical extracted from chrysanthemums, can be bought as ready-to-use sprays. Simply spray it directly onto an infestation (avoiding other insects) to kill current pests instantly, and deter future ones.
DIY White Mite Treatments
A few drops of peppermint oil on a damp cloth, wiped over the leaves of infested plants will clean off and kill white mites. It can also be used around the rims of pots as a deterrent, as mentioned above.
The easiest DIY treatment that anyone can make with ingredients you already have at home, is soap and water.
One teaspoon of soap, mixed into a spray bottle of lukewarm water coats and suffocates white mites when directly applied. It’s particularly useful for houseplants and can be stored at room temperature for as long as you need it.
Now You Know How to Get Rid of White Mites in Your Garden
White mites are a problem, but they’re not a disaster. They also don’t mean you’ve done anything wrong. During hot summer months, white mites are present in nearly every garden and most homes with houseplants.
In most cases, white mite infestations will be small and manageable, but to stop them from getting carried away, pick a few of the tips and tricks on how to get rid of white mites on your plants from this article, and take back control of your garden.
About Guest Author Lorri Hopkins
Hi, I’m Lorri Hopkins from Aussie Green Thumb living in Mount Barker, South Australia.
I have been growing beautiful Australian native plants, fruits, flowers and vegetables for as long as I can remember. Sharing that passion with my kids has made it all the more special to me.
Farm-to-table gardening is my forte and I’m grateful to be able to share what I’ve learned with other enthusiasts on this platform.