Finding a few small, wiggly creatures in your houseplant’s soil can be a surprise. If you’re seeing multi-legged guests, you might be dealing with millipedes in houseplants.
These soil-dwelling arthropods are common in moist, organic-rich environments. While they’re mostly harmless to your living plants, a large population can become a nuisance indoors. They feed on decaying plant matter, which is good for compost but not always welcome in your favorite fiddle-leaf fig.
This guide will help you understand why they’re there, if they’re a real problem, and how to manage them effectively. You’ll learn safe, practical methods to keep your indoor garden healthy and comfortable.
Millipedes In Houseplants
First, let’s clear up a common confusion. Millipedes are often mistaken for centipedes, but they are very different creatures. Knowing which one you have is key to choosing the right approach.
Millipedes have two pairs of legs per body segment. They are typically rounder, slower, and curl into a tight coil when disturbed. Their main diet is decaying leaves, dead roots, and other organic material in the soil.
Centipedes, in contrast, have one pair of legs per segment. They are flatter, move very quickly, and are predators. They eat other insects and spiders. While centipedes can give a painful bite, millipedes are generally non-biting and harmless to humans and pets.
Why Are Millipedes in My Houseplant Soil?
Millipedes don’t just appear out of nowhere. They are attracted to specific conditions that your potted plants might be providing. Understanding these attractants is the first step to solving the problem.
The most common reasons include:
* Excess Moisture: Overwatering is the number one cause. Constantly wet soil creates the perfect humid habitat millipedes love.
* High Organic Content: Soil mixes heavy with compost, bark, or peat moss offer a feast of decaying material. They can also hitch a ride in bagged potting soil you bring home.
* Decaying Plant Matter: Dead leaves left on the soil surface, rotting roots from overwatering, or old mulch provide a direct food source.
* Entry Points: They can wander in from outdoors through cracks, or be brought inside on a new plant, in a bag of soil, or on a plant that summered outdoors.
Are Millipedes Actually Harmful to Houseplants?
This is the most important question. For healthy, living plant tissue, the answer is usually no. Millipedes are detritivores, meaning they recycle dead stuff. They are not equipped to chew on healthy roots or stems.
However, problems can occur in a few specific situations:
* Seedlings and Very Young Plants: Tender, developing stems and roots might occasionally be nibbled if other food is scarce.
* Already Stressed Plants: If a plant is dying or has significant root rot, millipedes will accelerate the decay process. They are a symptom of excess moisture, not usually the primary cause of plant death.
* Sheer Numbers: A very large infestation in a small pot can physically disturb the root system as they move through the soil.
* Aesthetic Nuisance: The main issue for most people is simply not wanting them crawling out of the pot and onto floors or walls.
Step-by-Step: How to Remove Millipedes from Houseplants
If you’ve decided the population needs to be reduced, follow these steps. Start with the least invasive methods first.
Step 1: Isolate the Affected Plant
Move the plant away from your other houseplants. This prevents the millipedes from spreading to neighboring pots. Place it on an easy-to-clean surface.
Step 2: Manual Removal
For a immediate reduction, you can manually collect them. Do this at night when they are most active.
* Place a slice of raw potato or a piece of carrot on the soil surface. Check under it in a few hours; you’ll often find millipedes gathered there for easy pick-up.
* You can also gently scrape the top inch of soil into a bag to remove eggs and juveniles.
Step 3: Let the Soil Dry Out
Since millipedes need moisture, breaking this cycle is crucial. Allow the top few inches of soil to dry out completely before you water again. This makes the environment less inviting. Be careful not to stress your plant by letting it dry out too much.
Step 4: Remove Decaying Matter
Clean up the plant’s environment. Pick off any dead or yellowing leaves from the plant and the soil surface. Gently remove any old, decaying mulch or decorative moss.
Step 5: The Potato Trap Method
This is a highly effective, non-toxic way to trap them. Cut a raw potato in half and hollow out a bit of the center. Place the potato cut-side down on the soil overnight. The millipedes will be attracted to it. In the morning, lift the potato and dispose of the millipedes trapped underneath and inside.
Step 6: Consider a Soil Change (Repotting)
For a severe infestation, repotting is the most thorough solution. Here’s how:
1. Prepare a clean pot (you can use the same one after scrubbing it) with fresh, well-draining potting mix.
2. Gently remove the plant from its current pot.
3. Carefully shake and brush away as much of the old soil from the roots as possible. You can also rinse the roots lightly with lukewarm water to dislodge eggs and millipedes.
4. Inspect the roots and trim any that are soft, mushy, or dead.
5. Place the plant in the new pot with fresh soil.
6. Crucially: Dispose of the old, infested soil in an outdoor trash bin, not in your compost pile.
Natural and Chemical Control Options
If cultural methods aren’t enough, you can consider these controls. Always opt for the least toxic option first, especially indoors.
Natural / Organic Deterrents:
* Diatomaceous Earth (Food Grade): This fine powder is made from fossilized algae. It feels soft to us but is sharp and dehydrating to small insects with exoskeletons. Sprinkle a thin layer on top of the dry soil. Reapply after watering. Wear a mask when applying to avoid inhalation.
* Cinnamon: A light dusting of cinnamon powder on the soil surface can act as a mild fungicide and deterrent. It’s safe for plants and smells pleasant.
* Beneficial Nematodes: These are microscopic worms that you mix with water and apply to the soil. They seek out and parasitize soil-dwelling pests like millipede larvae. They are completely harmless to plants, pets, and people.
Insecticidal Options (Use with Caution):
* Insecticidal Soap: While most effective on soft-bodied pests, sprays can help with surface-dwelling millipedes. It must contact them directly.
* Pyrethrin-Based Sprays: Derived from chrysanthemum flowers, this is a natural insecticide. You can spray it on the soil surface. It breaks down quickly but can be harmful to beneficial insects and fish.
* Systemic Houseplant Insecticides: These are granules or stakes you mix into the soil. The plant absorbs the chemical, making it toxic to pests that feed on it. Since millipedes don’t feed on live plant tissue, these are often ineffective and not the right choice for this particular pest.
How to Prevent Millipedes from Coming Back
Prevention is always easier than cure. A few simple habits can keep millipedes and other pests away for good.
Perfect Your Watering Routine
This is the single most important prevention tactic. Water your plants deeply, but only when they need it. Always check the soil moisture first—stick your finger about 2 inches into the soil. If it’s dry, water. If it’s damp, wait.
Use a Well-Draining Potting Mix
Avoid dense, moisture-retentive soils. Choose or make a mix that includes perlite, pumice, or coarse sand to ensure good drainage and aeration. This keeps roots healthy and soil less hospitable to pests.
Inspect New Plants Quarantinely
Always inspect a new plant thoroughly before bringing it home. Look under leaves, along stems, and at the soil surface. Isolate new plants for 2-3 weeks away from your collection to monitor for any pests that might emerge.
Keep the Plant Area Clean
Regularly remove fallen leaves and debris from the soil surface and the area around your plants. This eliminates the food source that attracts millipedes.
Seal Entry Points
Check for gaps around windows, doors, and foundations where outdoor millipedes might enter your home. Sealing these can prevent indoor migrations.
Common Mistakes to Avoid
When dealing with millipedes, some well-intentioned actions can make things worse or harm your plant.
* Overusing Chemical Insecticides: This can damage your plant’s roots, harm soil health, and is often unnecessary for millipedes.
* Keeping the Soil Constantly Soggy: This is the root cause of many pest and disease problems. It’s better to slightly underwater than overwater.
* Ignoring Root Health: If you keep having pest issues, check the roots. Root rot creates the decaying matter that pests love.
* Using Outdoor Soil Indoors: Never use garden soil for your houseplants. It compacts easily, drains poorly, and is full of insects, eggs, and weed seeds.
When to Call a Professional
In almost all cases, you can handle a millipede situation yourself. However, consider seeking help if:
* You have an extreme infestation across many plants that doesn’t respond to any treatment.
* The infestation is part of a larger pest problem in your home’s structure.
* You suspect the millipedes are actually a sign of a serious moisture issue in your home’s walls or foundation.
FAQ Section
Q: Are millipedes in houseplants a sign of bad soil?
A: Not necessarily “bad,” but often a sign of soil that is too moist and rich in decaying organic matter. It indicates conditions that could lead to problems like root rot.
Q: Can millipedes in potted plants bite me or my pets?
A: No. Millipedes do not bite. Some species can secrete a mild irritating fluid if handled roughly, but it’s generally harmless. Just wash your hands after handling them.
Q: Will repotting my plant always get rid of millipedes?
A: It is the most effective single action if done thoroughly. The key is removing almost all the old soil from the roots and using fresh, well-draining mix in a clean pot.
Q: Do millipedes eat plant roots?
A: They primarily eat dead and decaying roots. Healthy, white, firm roots are not their preferred food. However, their presence can indicate that there is decaying root material present.
Q: What’s the difference between millipedes and wireworms in soil?
A: Wireworms are the larval stage of click beetles. They are slender, hard-bodied, and yellowish-brown, with just six legs near their head. Millipedes have many legs along their entire, segmented body.
Finding millipedes in your houseplants is more of a warning sign than a crisis. They are telling you that your soil environment is very rich and moist. By adjusting your care routine—mainly your watering habits—and keeping the plant clean, you can easily manage their population.
Remember, a few millipedes are actually part of a healthy soil ecosystem, breaking down organic matter. It’s only when their numbers grow or they venture out of the pot that action is needed. Start with the simple, non-invasive methods like drying the soil and using potato traps. With a little patience and the steps outlined here, you can restore balance to your potted plants and enjoy your indoor garden without the uninvited soil-dwelling guests.