Tiny, microscopic creatures are everywhere – In forests, deserts, and grasslands. In rivers, lakes, and oceans. On insects, birds, and mammals. In our homes and even on us – in our eyelashes and hair follicles. And they are in our garden soil and potted plants.
Some of these animals are problematic, but many are helpful, eating the “bad guys” and recycling nutrients…Like soil mites.
Mites in the soil? Should you get out the bug spray? Not so fast.
If you’ve read our article about building a living soil, you know that healthy soil is full of microscopic creatures as well as bigger ones too. These living organisms work in harmony to create a web of life that is mutually beneficial to the flora and fauna in it. From tree roots to nematodes, grasses to grubs, worms, and bugs, and yes, even soil mites – they all have a role.
Let’s learn a bit about these little guys and the role they play in our gardens before you decide to eradicate them.
What Are They?
Soil mites are tiny arthropods (invertebrates with jointed legs) that are related to ticks and spiders.
They can be white or brown and are 1 to 2 mm in diameter – about as big as the point of a pencil or the period at the end of this sentence. You’ll need a microscope to get a good look at them.
There are 20,000 identified species found all over the world. Scientists think there may be a least 80,000 species.
There can be as many as 500 soil mites of 100 different species in a half cup of soil in the garden. And they are incredibly beneficial.
Some species eat decaying organic matter, fungi, and molds. Others are predators that eat garden pests or their eggs. Others are scavengers and eat dead insects and whatever they can find.
Soil mites are nature’s recyclers – eating dead and decaying matter and returning it to the soil as nutrients that can be used by plants.
Their lives are mysterious and complex. The study of mites is called Acarology, and this branch of zoological science has only been around since the 1950s.
You’ll find different types of mites in different types of soil. They live in the top layer of soil in the garden and the lawn. They love the compost pile, and you might find them in outdoor potted plants and occasionally in your houseplants’ plants.
Oribatid mites are the most common. They are sometimes called turtle mites because of their shape or box mites because of the protective flaps on their bodies that can close uptight. They are drawn to decaying organic matter – leaf litter, dead plant parts, dead insects, and nematodes. They also eat fungi, molds, moss, and algae. They are slow in their life cycle (from 2 to 7 years!), reproductive rate, and movements. As they slowly walk along, they disperse nutrients (especially calcium) through their waste. Populations take a long time to build – their presence indicates a healthy soil.
Mesostigmata are predators. They eat smaller arthropods and their eggs and nematodes. They are quick and efficient hunters; some species eat spider mites. Some species of mesostigmata are used as biological controls for garden insect pests.
Prostigmata are very fast-moving creatures. When conditions are right, they reproduce quickly, too. Some eat decaying plant material or fungi and algae; others are predators or scavengers.
Astigmatid are usually found in farm soils with lots of rich, moist organic matter and a high nitrogen content. They are parasitic, living on small vertebrates and invertebrates. These mites are very tiny, with soft bodies, and are usually white in color.
You might see tiny white or brown dots moving on the surface of your soil. But because soil mites don’t cause any problems, you will not see any spots, holes, wilts, webs, or yellowing on your plants. Those symptoms are caused by pests such as spider mites, aphids, and scale and by plant diseases.
No, they are not a problem. They are very beneficial, and their presence indicates a healthy soil.
Some people don’t like the idea of them being in their houseplants. If you feel the need, there are ways to get rid of them.
So why the worry over them? They can carry parasites, bacteria, and the eggs of tapeworms. But you’re not going to eat the mites, are you? Well, you might – if you eat dirt or if you don’t wear gloves in the garden and neglect to wash your hands before you take a lunch break.
In the United States, your chances of getting a tapeworm are very low – only about 1,000 people get them a year, smostly from eating undercooked pork.
There is absolutely no evidence they attack or bite humans.
Do you have to kill soil mites?
No, you do not – especially the ones that are out in the yard. They do not hurt people, pets, or plants.
Some people may not like the idea of “bugs” in their potted indoor plants.
Soil mites are brought to houseplants accidentally. They can come in on a new plant. You can bring them in if you mix your own potting soil and use your compost as an ingredient or use outdoor tools on your indoor plants. Here’s what to do to rid your houseplants of them:
- Be sure the mites are present. They live in the top layer of the soil, so scoop out about a teaspoon of soil and spread it out. Use a magnifying glass to look for white or brown moving dots.
- The simplest way to get rid of them is to repot your plant in new, high-quality potting soil.
- Remove the plant and dispose of the soil. You can add this old soil to your compost bin (where they will be very happy), or just put it in the garden.
- Clean the pot thoroughly, removing any soil residue which might be harboring mites. Or buy a new pot.
- Gently rinse the roots of your houseplant to remove any soil before repotting.
- Don’t use tools that you use outdoors without cleaning them first.
- If you don’t want to buy new soil, you can sift your existing potting medium, removing all pieces of plant debris – dead leaves and stems, small sticks, pieces of bark, etc. This removes the mites’ food source. Again, wash the pot and the plant’s roots and your tools.
We don’t generally support the use of homemade concoctions for pest and disease control, and we are never behind the indiscriminate use of pesticides. Sometimes the use of these products creates more problems than they solve.
That said, you might find these recipes useful if you want to kill soil mites in your houseplants. But please don’t use it in the garden! Your plants need the nutrients these little guys recycle.
In a large container, add 4 cloves of garlic to 1 gallon of water. Allow to sit for four days, then remove the garlic and pour the water into a spray bottle. You can add a few drops of dish soap, which works as a sticker. Spray the soil.
Mix 1 teaspoon of cinnamon in 4 cups of water. Decant into a spray bottle, and spray the soil.
In a quart container mix ½ cup of 3% hydrogen peroxide with 2 cups water. Use this solution as a drench, pouring it over the soil. It will probably bubble, and it’s best to do this over the sink or outside.
With all these recipes, after a few days, check your soil with a magnifying glass. If you see the presence of mites, spray again. Removing dead plant parts removes the mites’ food source, so be diligent about that.
If you want to use an insecticide or miticide, be sure it is labeled for use on soil mites. Before purchasing a product, read the label carefully. The label tells you the pests it will treat. Otherwise, you are wasting your time and money and possibly killing other beneficial organisms.