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If fungus gnats are a problem with your houseplants here is an easy solution that has worked for me every time. Fungus gnats lay their eggs and develop into adults in the top 1/2 inch of the soil and they need moisture to survive. They have a 2 week life cycle.
The simplest way to break that cycle and get rid of them is to water all your plants from the bottom only and not let the top of the soil get moist. To be doubly certain of results I always keep closer to 1 inch totally dry and extend this routine for closer to 3 weeks, just to make sure.
Also before bringing plants home look around if you see any fungus gnats flying around the plant display area. You can also check the top of the soil for them by gently disturbing the soil with your fingertip. If you see any you will be better off to find another place to buy your plants. I hope this helps.
By Sylvia from Cobalt, Ontario
Gnats are a nuisance, especially when your house plants are covered in them. Get tips on getting rid of gnats on houseplants in this guide.
Ask a QuestionHere are the questions asked by community members. Read on to see the answers provided by the ThriftyFun community or ask a new question.
Does my Spider plant soil have fungus gnats? After watering my indoor potted plants, within about 36 hours, I noticed a soil surface infestation of what looks to be fungus gnat larvae. A large number of the larvae look like whitish thin worms from 1/4 in. to 1/2 in. long. I wasn't able to see the notorious black tip on the end of the body. The rest are about the size of a nail head with 6 legs and antenna.
EWW! I would take the spider plant out of the soil, shake the roots gently, wash in warm water carefully. I would use new potting soil that has been microwaved for about 30 seconds or so to kill any critters..let it cool for a few minutes. Then replant the spiderplant in the soil, and spray the spider plant with water with a small amount of dishwashing detergent to keep off bugs.
Absolutely, change out that soil! If you can afford it buy new soil.
Spider plants are really easy to propagate. Cut off some of the runners and root them in other soil just in case it does not take well to the soil-switch!
You can also give your plant out of the pot a bleach rinse, 1 TB to 1 gal of water. THEN get new soil. AND bleach your pots to kill any residue. Anytime you bring in plants in the fall from outside, seal them in a large plastic bag, spray some house/plant spray which will kill friends brought it. Must leave the plant in bag a couple days--read instructions.
I am so sorry I have nothing helpful to say...I just had to say, eww
Pour cold tea onto your plants. This acts as an insecticide! Good luck
It might be something called scale. If the outside of the pot is sticky and the plant has a sticky residue, then this is the likely culprit. You can save the plant by spraying it with an insectide and then repeating it in a week. Look online for pictures. Make sure to isolate the affected plant from any others in the house until it is cleared. I have saved several plants from this problem Good Luck.
How do I get rid of household gnats in potting soil?
By Tammy from VT
I have this problem no matter how many times I've changed the soil. I have no solution as of this date.
After you repot in clean soil, you might add a thin layer of sand to help keep them from getting to the potting soil. Best to use a growing sand that will be salt free.. a fast remedy is to mix up any liquid insecticide that is safe for the plant, even diluted down a couple of times and then use this mixture to water the plant, this will kill the larvae in the wet soil. There is also a product called Gnatrol you can use. It is Bt and only effects the larval stage so is slower to gain control.
Those are fungus gnats, and they are difficult to get rid of completely. Thankfully they seldom really harm the plants, though they are a real nuisance. In addition to the tips below, hanging a sticky fly strip near your plants will trap a lot of them. Another tip I have seen is to put raw potato cubes near your plants and change them every three days.
I was looking for a solution to my gnat problem. I opened a brand new bag of potting soil for some seedlings, and gnats came swarming out of the bag. I talked to my Aunt who has worked at a florist for years and said they microwave their soil for a few minutes and let it cool down before planting. It kills the larvae. Be careful, microwaving for too long can cause the soil to catch fire. Also the house will get a woodsy smell to it after doing this, she suggested microwaving some lemon juice to get rid of the smell.
First I soak planters in mild chlorine bleach then rinse. This water is poured over the gravel walk behind house and kills the moss/mold on pavement. We have plants lining walk and this has never bothered plants.
I have problems with soil gnats every year when I bring my household plants back into house after they've lived outside, plus, I have 3 cats. Finally found a solution ~5 yrs ago and works every time.
After repotting, add a thin layer of larger particle activated charcoal (can get at pet/fish shop) just on top of the soil. I then cover this with plastic mulch - some colors like blue or yellow enhance the colors of the plant. My favorite is blue, the green plants and/or pink blooms seem more vibrant.
The charcoal takes care of the gnats (as I've read they like moist soil) and the cats won't disturb the plastic mulch. If you have really large planters, I'd try the volcanic rocks that you might use for landscaping or grills. Had these in some really large planters with taller inside bushes. Cat could get into planter, but, jumped out quickly when she touched the rock.
Happy indoor planting !!
What are the little gnats in my potting soil?
Does anyone have a solution for getting these pests out of your house plants? I've used every solution posted for eliminating potential breeding grounds (and the flies themselves), but no one has touched on how to do this short of throwing away my plants.
By Allie A.
I have been having a problem with fungus gnats in and around my potted plants. I was told that if I diluted regular Listerine, 1 to 1 with water and spayed the organic soil mixture, the solution, would kill fungus gnats and their eggs that live in the manure.
If anyone knows this to be true please give feed back. Have tried other solutions, but to no avail.
Hardiness Zone: 6a
By Lady Belle 13 from Philadelphia, PA
To break the cycle of the fungus gnat you need to get rid of the larvae. It's very simple and easy. A slice of potato is all you need. Simply lay the slice on the soil of infested plants and the little maggots can't resist it. They begin feeding in the slice and now you have them where you want them. Throw the slice away after about 3 or 4 days and replace as needed. Of course there are other ways and this article may help. But making sure it's fungus gnats is key here because this trick won't work on other types. Hope this helps.
I have a fungus on my grass. I had a commercial service which I gave up on it and after that is when I got this fungus. It seems the grass is very weak do to all the chemicals this company laid on it and the fungus just took over. Any suggestion on a natural product, I'm afraid to use any more chemicals. Thank you.
Hardiness Zone: 10b
Carlos from Florida
You might want to change your pH. I'd call or go in to a local plant Nursery. Look in your yellow pages or Google "Plant Nursery & your City & State" & I bet they'll have lots of natural products. They may even be able to help you over the phone. You'll need someone who knows about Florida specific soil. If I remember (from when I was young & lived there) Florida has sand & not dirt for soil. Also, because it's "Tropical" I bet there's a lot of people with fungus in their grass. Call a local Plant Nursery & ask when the horticulturist that works there will be in.
* Don't use Vinegar, because it will kill your grass. You'd have to dilute it a WHOLE lot!
Beer on a day when its not going rain for a few days. The yeast in the beer will eat the fungus.
How do I get rid of little flying black bugs that seem to be in my potting soil? Where are they coming from?
I have had my fiddle leaf plant for several years. How do I get rid of the tiny bugs everywhere?
What can we use to rid ourselves of these gnats? I sprayed throughout the house with HotShot and it worked a little. I don't know if they were all asleep or just hiding away. They're everywhere. Thanks for your help. God bless.
Fungus gnats are in my closed top terrariums. I have tried every method that I have found on line (yellow paper with fly strips, and I have killed a lot, but not all). I found out that plants brought inside can have them so I took them all out on the front porch and put sand in the top. I discontinued watering on top and put a tray under them to water. (Someone suggested vinegar and that works.) I also put my potting soil in the freezer. I haven't put it in bake yet but will try. I have reworked four, washing the soil completely off roots, and cleansing the jars and rocks. After reworking two recently, one of them I discovered has a few gnats. I haven't tried insecticides because I had planned to sell them, but until I solve the problem completely, that's out. Help! I am working hard and everything works but not completely. If insecticides are used, do I spray the soil or all the plants?
Is there any way to get rid of gnats and larva in my new terrarium or do I have to dump all of the soil, rinse the plant roots and start over?
By Patsy A
ThriftyFun is one of the longest running frugal living communities on the Internet. These are archives of older discussions.
How do I get rid of little flying black bugs that seem to be in my potting soil? Where are they coming from?
Something that has worked for me is to put a bit of liquid dish soap into a spray bottle, diluted with water and spray the plants and the soil that has the bugs. I had to do it several times over the course of a few months, but I no longer have any bugs from the soil in my house. They seem to just die when they are sprayed, and the soap doesn't harm the plants. Mine are all thriving, so I've had no problem with that. (09/11/2004)
I agree with Melodie, and I have to add ... put 1/4 inch of sand on top of the potting soil. the bugs are laying eggs in the wet soil. so adding sand confuses them, as sand dries quickly, not enough moisture to hatch eggs. water gently but thoroughly. (09/13/2004)
You are probably buying the cheap potting soil that comes in the cheap plastic bags. This soil is not sterilized so all the bugs and eggs and stuff have not been killed in it. It is more expensive, yet it saves you a lot of grief in the long run, but buying the more expensive brand-name dirt in the nice bags will not have any bugs or eggs. It is also better for your plants in that it has peat moss and other fillers mixed into it already (and sometimes fertilizers as well) and the cheap dirt does not.
So you should add peat moss and perlite or vermiculite to lighten the soil. If you do not, the soil compacts around the roots, cutting off their air supply (roots need to breathe, too), causing your plants to die. So, better soil prevents pesky bugs and successful plants. That cheap soil is mostly meant for adding to a flower bed or using in outdoor planters. I have worked in a greenhouse and been a houseplant enthusiast for many, many years. And I have never seen a pesticide that can kill those bugs off.
Good luck! Heather (09/14/2004)
By Heather H.
Melodie's suggestion about the liquid dish soap and water in a spray bottle always works for me. Try it. (09/25/2004)
Being a thrifty person I will try the dish soap diluted with water. I'll put a good layer of sand on top of the soil as well. Thank you for this info!
Bye the way the bugs are in my apartment and biting me making me itch. I can't get rid of the flower pot because it was given to me by my daughter for a mothers day gift. (although, I have considered throwing the pot into the dumpster several times!) (05/08/2005)
I am having the exact same problem, and will not consider tossing either the plant nor the container.
I will however try the soap trick and the sand [maybe I can kill em twice as fast huh?] I hope so, I am sick of yawning and having to pick little bug's from my tongue after, I do however get a bit of exercise while watching T.V. by swatting at these darn pest's.
Also I did purchase the cheap soil this time as I was planning to only use it outdoor's, but I needed to transplant this one plant, I have several bags of it, anyone want it? lol
Thank you all
The best solution is to buy premium soil. If it's too late, soapy water in a spray bottle works but sometimes not permanently. Sand works well for the eggs in the soil. I heard Cinnamon works if sprinkled on the soil, for you Homeopaths. Also, Spanish moss or other decorative mulches deters gnats from finding new plants to lay eggs on. (03/12/2007)
I have them too! all over outside in my potted plants. I am trying the soapy water. I guess I got the one bad bag of miracle grow potting soil. Will anything else work? (06/16/2007)
I just sprayed my plants at work with dish soap and water and it must have worked. I tried it once before but it did not work. This time I added a lot of dish soap and I have found a lot of those little flies dead within a minute or two. Now I won't have to get rid of my plants. Thanks everyone for your great advice. Have a fantastic day! (08/09/2007)
I just read to pour rubbing alcohol in the soil, has anyone tried this? I hope it doesn't hurt the plant but I am desperate.
Editor's Note: I'm afraid it would kill the plant. The best thing to do is scrape off the top of the soil and throw it away. Then put some new soil on top. That should help get rid of the bugs. (08/21/2007)
I also am over run by the little buggers and they bite. Soap spray hasn't worked, chemicals haven't worked. I got these bugs from a huge expensive bag of Miracle Grow. I have been down this bug road before which is why I bought the good dirt- or so I thought.
This is what I'm going to do this time. I'm going to the store and insist that the bag be opened and checked for bugs prior to purchase. If no bugs I'm going to take all my plants out side in the back yard and remove all the dirt and gently rinse them roots and all clean with the hose. I'll then take them to the front yard where I'll have the fresh dirt and new pots and re-plant them. I'm then going to take them to my mom's house for a couple weeks till I'm sure all the left over flying bugs in my house are dead. When I see no more sign of bugs I'll bring them home. This is how desperate I have become to go to such lengths.
Three of my plants belonged to my great aunt who is no longer with us they are very old and very large, and one was purchased for our daughters funeral which means so very much to us. I just can't toss them out. Wish me luck. If this works I'll re-post and share my happiness.
My husband loved the post about the person who was picking the bugs from their teeth as he choked on one at dinner the other night.
I have these little guys to. I bought the most expensive Miracle Grow potting Soil, twice, and they have come from both batches. Doesn't seem to matter if you buy the good stuff or not. (01/05/2008)
Hello Ladies: I bought my first ficus indoor plant at Lowells Hardware Store, in the Garden Dept. Since I was strapped for money, the store worker provided me with a cheap bag of soil. Not knowing anything about plants, or flowers I had no idea what I was in for. I was worried about killing my new indoor tree and got instructions on watering and over watering, no one told me about bugs.
Three weeks after having my tree which was doing great, these little pest showed up. I refuse to get rid of my tree. I sprayed house and garden bug killer around the tree and find hundreds of tiny, tiny little black specks behind my love seat and couch and around the window seal. They also follow me upstairs and dive around my hair, or clothing.
I find them in my coffee, or food, only because I see little wings on them so I knew it was a flying insect of sort. They are so small they can virtually get into anything and be anywhere. I read about the soap and water thing tonight and immediately sprayed my tree and soil, please god let this be the answer. I also read about soap, water and cooking oil, what do you think about that? Help! Cheryl Phx, AZ (02/03/2008)
When you buy a new bag of potting soil, wrap a big bag around it and throw it in the freezer over night! Should kill em! I have done the water and dish soap thing too!! Worked for me, took a few months though! (02/26/2008)
I put sand on the top of the soil. They were fungus gnats, black little bugs around my new seedlings. I checked into it turns out if you are over watering they love to lay their eggs in the soil and eat the roots of your plants. Anyway let the soil get dry and try some sand or make sure to water from the bottom! (03/15/2008)
By Nicole B.
I too have had those annoying black bugs. I purchased a cheap bag of "potting soil" at my do it yourself center and low and behold, they started appearing. To stop the kill the little buggards, I also watered with the a solution of lots of dish soap and water in a cup and proceeded to drown the plant. I haven't seen any more yet.
Then I remembered you can also kill the little buggards and anything lurking in your potting soil by baking it in the oven at around 200 degrees for a half hour. Let cool and proceed to replant with your sterile soil. Both work well. Good luck to all of you. (03/15/2008)
I live in the Arctic, so we have lots of indoor plants. Over the years my friends and I have tried the soapy water, scrapping the top of the soil off, and a host of other things. The only thing that has worked on a consistent basis has been baking the dirt. It doesn't matter if expensive or inexpensive potting soils were purchased, the little flying bugs appear. It doesn't matter how much or how little water has been used, the little pests appear. All sorts of sprays and other concoctions have been tried...the flying horrors appear. Forget the sand, they arise as if it is Easter! Bake the dirt. Make sure you bake it long enough to kill off the eggs. Good Luck (03/22/2008)
I started noticing gnats in my house about a month ago. I killed some of them with a fly swatter. Then I started seeing smaller ones and suspected babies. It wasn't until I went on the internet that I discovered that they could com from plants. I thought they only came from fruits. I followed the info about vinegar and dish liquid. It worked! I also threw away the newest plant in my house, and replaced it with a newly potted one. So far no gnats. (04/04/2008)
I just started my own garden on my balcony in my new apartment and I have the same problem. They are in my new morning glory seedlings that just began to sprout. I'm afraid that they will eat my poor babies. I will try the soapy water but I still need to purchase the sand. Thank you all for this information. I hope it works for me as well :) (04/05/2008)
Found the best cure for black flies/gnats that come in potting soil. Son of a fly do these kill a hobbie! Anyway my mother had a tomato dust of 5% insecticide. I dusted the soil top heavily and watered. Results: hundreds of dead bugs! I tried the low % insecticide spray, but this powder of 5% did the trick. (05/27/2008)
I just opened a new bag of Organic Choice Miracle Grow and have tons of flying black bugs, too. If I didn't have to put the bag and bugs in my car, I'd return it. What a waste. (07/06/2008)
Does anyone know if (baking the soil in the oven) would help get rid of the little bugs? (09/12/2008)
That's all very interesting, I have had my plants for 3 years and now all of a sudden I have these little pest. All my plants are inside plants. Thanks for all the tips I will start on some of these suggestions right away. (11/17/2008)
I bought the best Miracle Grow potting soil with plant food already added. These little flying black bugs are driving us crazy. I will try the dish soap. Will it hurt the plant if it gets to the root? (11/24/2008)
Can anyone tell me what the ratio of soap/vinegar/water is for watering/soaking the plant? I want to kill the eggs too, not just the bugs. My husband is also very annoyed at these bugs, and wants them gone. (Although my 4 year old thinks they are cute and is totally against killing them. LOL) I want to be careful not to put too much of one ingredient in and kill the plant too. Thanks! (01/02/2009)
Also, will any dish soap work? I use an antibacterial dish soap but would that be too harsh? (01/04/2009)
I hope the sand works,those little bugs are driving me nuts. (01/11/2009)
I used the dish soap idea but to no avail! I'm so scared that if I put to much soap I might kill the plant. Can anyone give me a good ratio of soap to water that would work on a small plant? (02/25/2009)
Hi, I have this problem too and just found out through wiki answers.com that these are fungus gnats.You get rid of them by setting trays of vinegar out near your pots. Need to get rid of all the bugs, including their eggs that hatch and become adults - so could take time. Also,you can buy those yellow sticky traps. At least this is something to try. I hate those things, they try to fly into my eyes. Good luck. (11/29/2009)
I saw a link that someone said to use hairspray. Today I took out the can and sprayed the top of the soil and turned the soil over and a zillion little flies were hopping all over. I sprayed the top of the soil again and now the little black flying bugs are down to about 2 every 5 hours. I also sprayed the little white "worms" that we coming to the top and it worked on them also.
The hair spray stops them from flying and they die. Sure was glad I had a new can of hair spray on hand. Good luck (02/07/2010)
BT has been highly recommended to get rid of maggots of fungus gnats in the potting medium thus preventing plants specially seedlings from being attacked by these worms. It is not toxic to plants or animals and is commonly found in mosquito dunk products and in granular form as well. Follow the directions and save your plants! (05/24/2010)
Here is a pic of the larvae. (05/24/2010)
My mom suggested making a sort of tea from a couple cigarette's worth of tobacco and spraying that on the soil. She's had good luck with it, I guess.
I have some outlandishly expensive Miracle Gro potting soil. Didn't help. I expect that these wretched bugs live just about everywhere so it doesn't matter what soil you buy, they find their way into the house through a window or door and voila! They're all yours.
I carefully pulled my amaryllis out of the pot and rinsed it in the sink. Then I took ALL the dirt out of the pot, put in in cake/pie/cookie/bread/any other pan I could find (be careful, the gnats will fly in your face while you do this. Yuck), and baked it in my oven for 30-45 minutes at 325 degrees. If that doesn't kill the little buggers nothing will.
In the meantime I put a small amount of wine in a pan and warmed it gently on the stove for about 90 seconds. It should still be comfortable to put your fingers in it, but just warm enough to smell. That should attract the bugs and drown them (and hey, they'll die happy drinking cheap sangria! A very humane way to take care of them).
Repot the plant, leave a dish of wine or vinegar next to the pot for a week (you might want to change it every couple days), and water with dilute dish soap for a couple weeks to make sure they're all out of your house.
I think I just combined all the previous methods. I hope my amaryllis survives the repotting. (05/30/2010)
So I've had these little super annoying bugs flying around for a week. My one little plant has sentimental value to me and is out on the deck. I wanted to get good soil for it and bought the premium Miracle Grow organic potting soil that was the most expensive that Wal-Mart had.
Finally started googling today about little flying bugs because no matter how many I killed more would come and saw some people mention it could be potting soil.. went back to the opened bag I used for my plant and bam, bunch of the evil little things. I've read like 7 or 8 other posters mention Miracle Grow too, buyer beware. God do I hate those bugs. Going to need to transplant my plant to new dirt now, but how likely is it that I'll get another bad batch of soil? (08/20/2010)
I have a huge problem with these nasty little critters; I agree they have invaded our home via potting soil we have purchased.
I have tried numerous chemical bug sprays, even granular insect control to no avail. After visiting this forum a little over a week ago, I thought I'd give the "tobacco juice" formula a try. I found various formulas on line. Most of the recipes include a brew of tobacco, with a measure of liquid dish soap and mouthwash added. I used the cigar butts from my ashtray and trash can to make the tobacco brew in very hot tap water (overnight steep), added the other ingredients and strained through a fine mesh screen.
Less than a week ago, I sprayed one of my large planted pots (on the soil to wet thoroughly) which had literally thousands of these minute beasts in it, and it looks like the juice is working! It isn't a "kill on contact" solution, but I have to say I am extremely encouraged by the results after just less than a week. We'll see... (03/24/2011)
I have at least 50 houseplants. I re-potted many over the years and have never had a problem with gnats, now I do. I try to let the soil dry out as much as I can without harming the plants.