friend or foe ?

[Normans Mum]

Everything seems to be growing well in my greenhouse, but I have noticed on the soil surface of most of my seed trays and pots, there are tiny flies. they don't seem to be causing any problems with the plants or seedlings but are very persistent and to be honest a bit annoying. Is this anything I should be concerned about? I'm meticulous about greenhouse hygiene and so I don't really understand where they are coming from and why they are hanging around.

[Matt94]

are the flies white - if they are they will be white flies, i usually get them every year in the greenhouse and i dont think they do much harm, marigolds usually deter them (its a bit early in the season for them tho). heres a link to whiteflies :http://www.google.co.uk/url?sa=t&rct...WBPGs22oMjKJJQ

[rustylady]

They are scariad flies, or compost gnats. Sciarid Fly - how to control these plant pests

[Normans Mum]

Thankyou for your help. Will try to keep it under control. : )

[Jeanied]

Oh bother - I have loads of these in my seedlings. And all over the house...

[Normans Mum]

OOoops, Jeanied.
Let me know how you deal with them. I think I might have to invest in some nematode defence.

[Two_Sheds]

They are a nuisance when the compost is too wet ... having said that, you can still get them if you're frugal with your watering. I've got about 50 squished on my bedroom windowpanes

[jdlondon]

Can't find these nematodes on the B&Q website - anywhere else sell it or is it something you can only get online?

[WendyC]

I read a tip somewhere that they love almond oil (from health food shops) so I put milk bottle lids with a little oil in them and the flies go swimming and never come out. Doesn't get rid of all of them but reduces numbers.

[Two_Sheds]

I read a tip somewhere that they love almond oil

That would be me: it wasn't a scientific trial or anything, I just happened to notice that the fungus gnats were attracted to the oil, stuck to it and perished

It might also work with olive/rape/sunflower oil, I don't know

[taff]

or if you have a steady hand, do what I used to do when the flies circled round the lights...get the hoover out

[jdlondon]

Leaving my glass of juice out seems to do the trick too, unfortunately, and my tea!

But it was more the eating of roots I was more concerned with. I honestly thought the flies came after the roots started to rot, didn't realise they started eating and began the damage themselves. I think they are what finished off my chowchow.

[rustylady]

I think they are what finished off my chowchow.

Chowchow

[jdlondon]

Also known as chayote: https://en.wikipedia.org/wiki/Chayote

One of the first things I tried to grow. Did really well, grew half metre tall, and then the flies came.

[rustylady]

Where were you growing it?