Hi again it's Jason from Fraser Valley Rose Farm and today I want to talk to you about how to get
rid of fungus gnats which are a particular pest to house plants but also in situations
like propagation where you're misting your plants or keeping them in humidity domes like the ones
behind me the soil stays moist for a while and you get fungus gnats i'm putting up some pictures
and a video of the fungus gnats now they're pretty easy to identify they look like a tiny little
mosquito but much much smaller in size they would be more similar to something like a fruit fly or
a shore fly for which they can be mistaken but chances are if they're hanging around your plants
and their soil it's fungus gnats you're dealing with so i'm going to deal with in this video
how to get rid of them first because that's probably what you came here for then after
that i'll talk to you about how to identify and to prevent them in the future in trying to get rid of
your fungus gnats i'm going to focus on biological controls and there's a couple of reasons for this
i guess you could go back to the philosophical preference for not using chemicals on your
house plants and in propagation but that's not really the main one the main reason is because
the fungus gnats live a good portion of their life stage as fungus gnat larvae in the top layers of
your soil and in that form they're well protected from most chemical controls which would spray on
the surface but not persist long enough and not come in contact with enough of the larvae to
really wipe them out so those larvae actually are the life stage that cause the most damage a little
flying black things don't really bother me much at all they're more of an annoyance than anything but
when i pull up my plants in propagation and i find these little translucent wormy things uh chewing
on their newly developing callus or roots that bothers me a lot i'll show you a picture here so
you can recognize the culprits for those guys you really should tackle them with biological controls
that also inhabit that top layer of the soil the first one i'm going to point out here is
a nematode called Steinernema feltiae it's in a product here called pot poppers this one comes in
a little sachet i'll open this up and show you how to apply it and i'll insert a clip of that as well
and you just water it in and then the steinernema inhabits that top layer of soil and it parasitizes
the fungus gnat larvae and kills them the second one i'm going to talk about here i'm just going to
put this down second i'm going to talk about is a different product called uh in this case mosquito
dunks or you can also get this as mosquito bits mosquitoes are the same family as fungus gnats and
this is a bacteria bti or bacillus that infects their intestinal tract i think and kills off the
young larvae so that's what this product does now one advantage of this one the steiner nema is that
it's a generalist these guys will go after not only the fungus gnat larvae but also thrips larvae
so if you have a problem with thrips this will do double duty this one here is only very specific to
the members of the fly family so mosquitoes fungus gas shoreflies fruit flies that kind of thing now
one last one i'll talk about it isn't as easily available in a product as these ones i have here
but hypoaspis miles is a little predatory mite that also does double duty it lives in that
soil zone and it's a it's a mobile predator it goes around really chewing up the larvae of the
fungus gnats but also of the thrips so it's a good biological control to have around again not
so much in a dry product that you're going to buy on amazon but you'd want to go to your
your local grow store or your local horticulture distributor somebody who distributes biological
controls and that would be a good one for that purpose a word or two on prevention and detection
it pays to let your soil dry down a little bit between waterings which i know is easier said
than done when you're doing propagation you don't really want a dry environment in propagation so
you're misting or keeping things in handy domes but for your basic house plants if you can let
that surface dry down a little bit that will make the fungus gnats a little less likely to
move in now these guys here i have been keeping in a humidity dome because i've been trying to
get them to thrive after dividing them and so that top surface of the soil you can see is quite
wet so something you can do in that case is you can go to a dry mulch like this here these are
fine cedar chips and you can take these and they dry out on the surface very very easily
and then you can top dress the soil with that obviously all the way around and that will help to
maintain a dry soil surface when the fungus gnats that are flying around try to lay their
eggs that makes it harder for them to access the soil down beneath and should
reduce them reproducing to the fungus gnat larvae one more thing i'll show you here just real quick
is that there's a way to detect them now this is not a control these are yellow
sticky cards are a way to detect them in your grow area so here's one of course i
nicked that from a local greenhouse underneath one of their propagation benches you can see
over a long period of time they've had lots of fungus gnats and other pests that they can detect
well of course you can trap them on sticky cards like these you can get various shapes and forms
the traps again don't work as a control necessarily but they will tell you when
you start to have a problem and that may give you kind of a heads up to move on towards action
one last thing i'll say is that once you've detected them once you see flies - the fungus
gnats flying around you can use the controls i've talked about you can combine that then
with a spray as well above the surface to knock down the adults that should help to
eliminate the adult generation at the same time all right that's all i have for you
on fungus gnats today i hope it's been useful if you have any questions about it
please drop those below the video and i'll see what i can do to help thanks so much