Help please re houseplant compost

I'm seeing loads of people complaining about wee black flies coming off the compost. Anybody recommend good compost? I can't stand gnats, midgies and flies in my tiny livingroom!

 

I believe the black flies come because the compost is too wet - maybe poor drainage. I always mix a little bit of coarse grit in with compost, even for house plants.

 

I'll get some, ty

 

It is the permanently wet surface of the compost that they live in.
Try watering from the bottom for a while and make sure the top inch dries out before adding more water.

You could top the pots with grit if you don't want to repot.

 

Just this minute bought gravel on amazz and will do that pete, ty!

 

Two things that do work against them -

Get a box of standard matches, eg Swan Vesta and places several per pot into the compost, match head down. That seems to work ok for light infestations.

What fully cured our houseplant scarid fly problem was a watering made up from this product. It also worked well in our greenhouse.
https://www.amazon.co.uk/Summit-responsible-solutions-Mosquito-116-12/dp/B0001LE1VC?th=1

 

It would work very much cheaper to just water from the saucer the plants sit in or cover the compost with gravel! Keeping the surface dry is probably the most effective way as that way they can't feed on the decomposing compost.

 

I was told to do this a while back, when I moved here I had loads of plants and they were plagued by these wee flies. I did water from the bottom but it didn't work balc.

 

FYI this is why they always seem to fly near you -

Fungus gnats are attracted to carbon dioxide, which is why adult flies become a nuisance to humans as they are drawn to the carbon dioxide from our breath. They also have a habit of not settling, so they continue to fly around people’s heads in an erratic matter, even if waved away. Fungus gnats pose no danger to humans – they are unable to bite or penetrate human skin as their mouthparts are only capable of taking in moisture from the soil.

We have plants in most rooms and a single good watering of a solution from those Mosquito Bits kept our house clear of them for almost a year.

 

Best way to avoid the little blighters is to water less. My trusted method is to poke a finger into the compost and only water if the compost is dry down to first finger joint.

Then I forget to water altogether and only notice when the plants start to droop.

But no nasties flying around here apart from seed sowing period when there is always moist compost around.

 

I would disagree with watering methods to be of a help. Some plants just would prefer substrate to be moisten evenly from the top to the bottom when watered (like african violets in little 5cm d pots). It's important initially to get "fungus gnats free" compost. Over past years I used Jack magic all purpose (till when it stopped to be peat based), john innes nr.1 and 2, now Evergreen multipurpose, also verve's seed sowing.I have different plants, so mix substrates by myself adding bark, seramis, clay balls, perlite, vermiculite etc., occasinally washed coco coir. Didn't see these flies.

 

I've not seen any fungus gnats in years.
Years ago would see the little worm like creatures in the top of compost, but not anymore.

 

A few months back we had a veritable plaque of them in our kitchen but I didn't do anything to get rid of them - the kitchen itself did all the work! How?, you might ask. Just the stickiness that comes from oil that evaporates while frying & sticks to the tops of the kitchen cabinets!

For as much as we try to reduce our use of oil in frying over time this invisible film builds up but it acted like glue to the poor flies as 100s of them became stuck to the Venetian blinds & the tops of the cabinets! Hardly seen them in the last few months! The adults obviously couldn't reproduce therefore once the last of the eggs hatched & became flies they also became stuck & died! Not very nice perhaps but since I cleaned all the surfaces again I hardly seen any!

 

I'm gonna get me some sticky kitchen cabinets.

Sometimes they can be confused with fruit flies in the summer months but fungus gnats are definitely a problem of over wet compost.