HELP! Gnats infesting everything !

[plantshaman]

A few months ago i decided it was time to re-pot many plants and take some cuttings to keep inside , safe from the spider mites killing everything outdoors.

  So swim spent 100 dollars at home depot on soil and pots. Within a few days we noticed the soil was infested with little black gnats. Although i'm not sure of their identity i don't think its a fungus gnat. whenever the house is around 69-74 degrees they hatch and it gets crazy . I'm talking hundreds of gnats. Its like the soil is alive and moving .

  I've tried all sorts of things with no luck . First I tried sprays. I bought garden safe house and garden spray which was effective for a few hours at a time but because of the large amount that had to be repeatedly applied to see results it started to kill the plants and i was worried that spraying it on the soil would kill the plant . I've tried tobacco, peppermint castile soap, and assorted peppers all of which where not very effective, even when all combined in one cocktail of death. I've given up on sprays because i'm spraying the rock and soil on top . It only kills the adults on top. It would probably help on leaves .

 rocks on the top of the soil, no help .  

electric pest control, the kind that uses sound ... no help

Now i've moved everything outside except for one plant that would die outside . The gnats are going strong outside and will surely infest the flower beds soon where my most prized plants grow. some of the tiny seedlings and more fragile plants of course are dieing.

The 2 pots indoors i covered up the soil with thin cloth and duct tape to hopefully break their life cycle. Its been 4 weeks with them covered and no improvement . You can see through the cloth and the white rock is nearly solid black from live and dead gnats . Some still escape into the apartment . I'd say 25-100 a day mostly depending on the temperature.There must be many hundreds hatching a day.

my last resort is to extend the pots up 12 inches by making somethingi out of plaster or concrete.Then get sand and cover the soil to hopefully trap them deep enough that they can't ever get out . hopefully if it worked i could remove it after a while.

Can someone please help ?! if i find one more gnat in my cup of yerba matte i'm going to explode !

[OBODAOUR]

Heya,
 You could try removing all the plants from the soil and microwave sterilizing the soil and then repotting. That should kill any eggs/bugs that are in it. Good luck!

Peace
ObOdAoUr

[laughingwillow]

Adding a layer of diatomaceous earth to the surface of the potting soil will allegedly kill the gnats when they attempt to surface from the soil.

I've found that avid used as a plant systemic also kills gnats. (Avid is gone without a trace 35 days after application, so use accordingly.)

lw

[VajraPirate]

I would like to add that covering the surface of your soil with sand should break the lifecycle of your infestation. Any eggs laid in the soil will contnue to develop, but it will prevent anymore from being laid.

[Stonehenge]

The diatomacaeus earth should do the job. You can get it cheap at a pool supply company. Mix a little with your potting soil or just sprinkle some on top. Works like a charm.

[plantshaman]

thanks , i found diatomacous earth at home depot it was really cheap . 15 dollars for 25 pounds . I mixed it into the top layer and sprinkled some ontop but there where still alot of gnats once the moisture from the soil soaked into the D.E. .  yesterday i added another layer just enough so i can't see any soil and there are just a few gnats now ... it seems to be working.

can too much D.E. hurt plants ? Is it still effective if its wet or do i have to start bottom watering till they are all gone?

[laughingwillow]

Give it time. There will prolly be some eggs hatching for awhile. The DE cuts up the gnats when they crawl through that layer. Top watering should be OK.

lw

[winder]

The yellow sticky traps do a great job at catching gnats.

[Stonehenge]

Sticky traps work best on whitefly which are attracted to it. Gnats don't seem to be attracted to the color yellow but will fly into the traps by accident and remain stuck. A good trick is to put the sticky traps close to the light you are using. The flies fly up toward the light, are attracted to the yellow and get stuck. It also will trap quite a few gnats.

DE works fine when wet and will not hurt the plants any. It helps with ants but ants are smart and tend to avoid it.

[plantshaman]

now that i added a little more D.E. i'm seeing alot of improvement . There are few gnats only old ones attracted to the moisture looking to lay eggs i assume .....

today  i saw that since there is a layer of white on top i noticed  there are tiny little red bugs which look like maybe they are spider mites or some other mite . I have a horrible mite problem out in my yard but things have always been ok inside ....

The bugs seem a little too big , too red , and they are not on any leafs that i could find. I would describe their shape as being like a beatle or mite.  there are no webs that i can see.they almost look like a flea but a little smaller.they seem to move around faster than the spider mites cuz they are larger i assume.

I'm hopeful the D.E. will take care of them too , whatever they are ?

what shoudl i do now ?

does anyone know what they are .

[kosmicjourney]

Try this stuff called "1600 X-clude" (Like $15 a 20 oz. can). It's a timed release pyrethrum. You may or may not find it at your local hydroponics shop. Got mine at our local Worm's Way. You may have to use it more than once. You spray the stuff in 5 sec. blasts. Good Stuff! Oh, and use those sticky cards as an indicator as to how bad your infestation is.

peace,

kj

 

[Stonehenge]

I just use safer's soap. I don't think I've seen a bug yet it won't kill and it's safe on plants.

[laughingwillow]

Do you have any luck with safer's soap and spidermites, stoney?

lw

[TroutMask]

Warning: Pyrethrin can do terrible things to a Salvia D plant. I like to use it on anything else, but Salvia got pissed and dropped all her leaves. Still came back and without bugs, but it was scary.

-TM

[Stonehenge]

As a matter of fact I wiped out a spider mite infestation on a couple of my outdoor voacanga plants. Safers will definately kill spider mites but as most people know, they are tenacious and come back. I had to spray every day for a week, mostly under the leaves and then every 2 days for a couple more weeks before they were finally gone.