I have used the solution and will let you know whether that solved the problem, at least on the adenium plants.

Crissy, good luck on your battle with the fungus gnats! Hope one of the solutions suggested will work for you and your plants.

Bti does kill fungus gnat larvae, but Bti does not thrive in house environment (not sure about greenhouses). If you apply Bti in aqueous solution, you will need to reapply in 5-7 days to kill the next brood that survived the first application because they were eggs.

So, if I put sand on top of the soil of the potted plNts, that would help?

I don't know if it's have fungus gnats, but I know I seem to have a healthy invasion of whiteflies. Some of my plants even had them while they were outside in the summer.

The sand covering is said to prevent access for the laying of more eggs. If gnats have access to drain holes, that won't prevent the adults from being attracted to pots. Sand on the surface will migrate down into any tiny air spaces whenever you water, possibly causing roots to suffocate & rot (overwatering) over time. IDK what the gnats might think about it, but putting tiny particles like sand in pots is a recipe for inviting root rot.

Any time I read "sand" in the context of potted plants, I substitute "grit". At least 1 mm in diameter, preferably 2.5 mm.

Or shredded bark. Coarsely shredded bark keeps the surface quite dry, but I wonder about adult gnats crawling between the bark chunks to reach moist soil mix.

I agree with Tiffany:

>> Sand on the surface will migrate down into any tiny air spaces whenever you water, possibly causing roots to suffocate & rot (overwatering) over time. ...
>> putting tiny particles like sand in pots is a recipe for inviting root rot.

At one time, I shopped around for "coarse sand". The coarsest sand I ever found was still 60-70% "fine or medium".

Sand can benefit outdoor soil but I don't think it has a role in soilless container mixes, which need faster drainage than outdoor soil.

I use the gravel they sell for parakeets, not sand.

I have gnats in my kitchen and living room. It's basically all on the first floor of my house. I had a bad gnat problem last year in my master bathroom and found out the source of the problem was the subfloor getting wet from a leaky toilet. That problem has been resolved. Since around mid August I've had a similar problem in my first floor. I've been trapping some of them with apple cider vinegar. The problem is they keep coming back. I do have some plants in the kitchen that have constant standing water in them. My husband has the green thumb in the house. He's always kept the plants this way. I don't see any bugs flying around the plants nor do I see any eggs. Can eggs or larvae be invisible to the eye? I'm wondering if they're in the water and we just don't see them. The bugs do look like fungus gnats. They're black with clear wings and are weak flyers. I appreciate any insight/help with this. Thanks!

Welcome to NGA, @BugLady !

if the eggs/larvae are in the soil of the plants it would be highly unlikely that you would see them. I would recommend moving the plants out of the kitchen (to the outdoors, or a garage, if possible), and letting them dry out considerably. What kind of plants are they? Would it be possible to remove essentially all of the soil from the plant(s) and repot them in new planting mix?

I used sand many years ago, when I got them. It was silicone sand, for sand blasting, Sand with tiny particles of glass. The glass cuts the larvae as they become flies and try to fly out. Regular sand may be of help. I just know that when I used it it was the glass in the sand that was the lethal weapon. It did work. I found it messy, and I scratched a glass table a bit with it, so protect furniture, it will scratch. I learned to blow it off with a blow dryer to get it off furniture, after I moved the plant off the table of course. I removed the sand as soon as the gnats were gone. I would not use it today, BTi is what I would try.

Good suggestion, Laurie -- I had never heard of BTi, but here's a description of "Gnatrol" on the Amazon site: https://www.amazon.com/dp/B003E7BGTU/

I would still remove those plants from the kitchen, until there is no more evidence of the gnats

I'm not currently experiencing an invasion of fungus gnats, but I anticipate their arrival when I bring a number of plants inside. I'm glad to know that BTI, short for the harder to pronounce Bacillus thuringiensis israelensis, might halt any that try to hatch in my plants.

BTI comes in a number of forms. I tend to use the 'dunks' or 'dunking' donuts' as I call them. Round here we got more than our fair share of skeeters. BTI will kill the larvae but not the adults. Wherever I find any standing water, even a few little drops in the bottom of a clay saucer, I'll toss in some BTI. My neighbors sometimes give me the fishy eye when they see me patrolling the alley with the dunks. (or bits)

I don't have any at the moment, but I know that BTI also comes in liquid form. Hmmm. Wonder if that would be cheaper in the long run? (Don't mind me. Just thinking out loud.)

If anyone wants to get techie re BTI, here's a link to Wiki:
https://en.wikipedia.org/wiki/...

Weedwhacker said:Welcome to NGA, @BugLady !

if the eggs/larvae are in the soil of the plants it would be highly unlikely that you would see them. I would recommend moving the plants out of the kitchen (to the outdoors, or a garage, if possible), and letting them dry out considerably. What kind of plants are they? Would it be possible to remove essentially all of the soil from the plant(s) and repot them in new planting mix?

They're green plants. I'm not sure of the type. They're not in any soil. They're in clear vases filled with water. I can see the roots of the plants and see no eggs or larvae.

Buglady said:

They're green plants. I'm not sure of the type. They're not in any soil. They're in clear vases filled with water. I can see the roots of the plants and see no eggs or larvae.

In that case... I think the suggestion to use BTi would work perfectly for you

I started to add a comment but didn't want to be misinterpreted. (Could happen.)

Let me just say that I agree with @Weedwhacker that for a green plant in water with roots and no visible eggs or larvae (would they be visible?) you're best bet might be to use BTI.

A warning, tho, about BTI dunks. When they've been in water for awhile they tend to get all crumbly and would detract from the look of your plant and might muddy up (not right term but brain's on autopilot right now) the vase. Try to find the liquid form of BTI. If memory serves, and I think we all know by now that it might not, the liquid BTI is a clear liquid.

Very useful information here! I recently got rid of a fungus gnat problem, which I believe originated when I brought in my tropical hibiscus last fall. Duh! Of course there were bugs, it has just spent nearly half a year outside. This year we will repot before we bring it in, and then it's staying inside for good. The pot/plant is too big to lug outside in spring and then repot and bring back inside in fall.
Anyway, the gnats infested all my other plants. We repotted--they were still there. Used Gnat Nix on top of the soil, which didn't work. After months of trying natural solutions, we got rid of ALL the soil and my plants are sitting in vases or water bottles with just water. We haven't seen a gnat in almost a month. I went to repot one to test it out, and the bag of soil had larvae! Admittedly it was an old bag. I went to put Bionide Systemic Granuals in the soil and saw all this movement. So, when we repot soon, I will be throwing out any unused soil. Hopefully that stops the issue before it restarts.

Lauren! Sounds like you have a good gnat control program going.

@Gasrocks, Gene always gives great advice. He recommended AzaMax just the other day. I have not checked stores for this yet.

On Line:
AzaMax™ controls target pests on contact or by ingestion. The product acts on pests by way of repellence, anti-feedance, and interference. It is all natural, the active ingredient is Azadirachtin. I have found it on line in pints and up to gallons. It seems a bit high, but is actually cheaper than my Neem oil. My first search I only found large containers, but the smaller ones are available.



See Gene's Post below:

gasrocks
Sep 26, 2016 8:57 AM CST
I have tried almost everything over the years. I winter about 1600 plants inside. Means they are close together. Means pests are my #1 problem. Not anymore. I found Azamax. Now, I could not live without it. In a way a concentrated Neem Oil spray. Not too expensive. Can be sprayed on almost everything. Safe to use around children, pets, fish. Every other pesticide I have seen says do not use around fish. Does not smell up the house. Can be used indoors or out. Safe for honey bees. Kills Fungus Gnats, whitefly, mealy bugs, scale, spider mites, cabbage worms, Japanese beetles, etc. etc. Does not kill on contact. Works a different way. Think of it as birth control for bugs. Makes the plant taste bad, stops bugs from growing, kills eggs. It works! That's the main thing. Ask me for more details if you like. Gene

Buglady, the gnats you are seeing are not the same as fungus gnats that are commonly found thriving in damp soil of potted plants. Apparently, yours are coming from a different source and require a professional exterminator to determine how to treat them. The advice given on this forum is specifically for fungus gnats that do live in damp soil, but those remedies are unlikely to work for your gnat problem which is not limited to your plants.

[quote="lauriebasler"] @Gasrocks, Gene always gives great advice. He recommended AzaMax just the other day. I have not checked stores for this yet.

On Line:
AzaMax™ controls target pests on contact or by ingestion. The product acts on pests by way of repellence, anti-feedance, and interference. It is all natural, the active ingredient is Azadirachtin. I have found it on line in pints and up to gallons. It seems a bit high, but is actually cheaper than my Neem oil. My first search I only found large containers, but the smaller ones are available.


Be advised that AzaMax is a fairly potent pesticide and all precautions must be taken when using it, especially if there are pets, fish or children in teh household. Read the label VERY carefully before using this or any other pesticide.