Tip for Sciarid fly (Fungus Gnats)

I've been having major problems with Sciarid fly in my epiphyllum cuttings since the beginning of November after I made the mistake of buying in some cheap bulbs to plant up as Christmas gifts it was literally a plague of the horrible little beasties! I was getting through so many sticky fly traps... however a friend on another discussion group suggested I try mixing 1tbsp of Bicarbonate of Soda to 1lt of water and spray the plants and soil every couple of days and after my first application I haven't seen a single fly! obviously I will have to repeat to get the ones just hatching but I'm onto a winner!

 

I was told to only water from the bottom, and keep the compost on top as dry as possible.

Trevor

 

Hi I was told use almond oil in a small glass which attracts them and they drown

Spruce

 

It's hard to water 90 cuttings from the bottom, the problem was that not all the plants were being watered at the same time so the soil was always moist in at least one pot... I didn't think I'd have a problem as I'm using nothing but coir but it turns out they were eating the small roots and perhaps the bacteria breaking down the bonemeal

 

I've had the same issues Aesculus. I repotted my indoor plants this summer and the gnats drove me mad. I was told by a local garden centre they had come from B & Q's Verve Multi-purpose compost which I had used. Apparently to cut down on cost they have stopped screening the compost before it's sold.

I have since repotted with different compost, problem solved!

 

I'd like to update and say don't try this tip, it makes your hands smell horrible! every time I touch my plants now I'm forced to wash my hands straightaway as they smell horribly of baking soda... with any luck after summer of spraying they will be free of the smell

 

Far be it from me to say this Aesculus, but are you not keeping them too wet during winter if this is a problem?
Also, I always mix a bit of sand in the compost, it seems, by drying out faster, to stop them being a problem.

I never Knew bi carb had a smell.

 

I water no more than once a month Pete they survive because the plants are not all watered at the same time and so jump from pot to pot so too speak I've had all the plants almost bone dry and yet once I water within about 2 days they would be back so I think they must be able to survive drought at certain stages of there grub stage or as eggs... since I watered most of my cuttings with an insecticide containing Thiacloprid I haven't seen many at all

 

I was told that too, it didn't work for me. What is the value in spraying the plants the gnats live in the soil. I'll try this, the little blighters wait until I'm watching something really interesting on tv the hover 4 inches in front of my nose and how are they able to suddenly go in any direction at 100 miles an hour when I try to squash them?

 

I've just read in 'General Gardening' that microwaving or freezing the soil works but I haven't tried it yet.

 

Sheal no need to read "General Gardening"' you can find it all out on GC

I am going to Zigs on you
Spruce

 

I'm assuming that's before you grow plants in it

 

If it's veg growing in it - it can all be cooked at the same time.

 

Sheal
Boil in the bag comes to mind