Gnats like peat based mixes, so using a gritty mix would help. They also like moisture, so just letting the mix dry out between waterings should also keep them at bay. Besides, succulents shouldn't be kept too moist anyway :-) I wouldn't use sand on top.

No, no, no & no to sand, it is not good for any plants, especially not succulents.

Agree w/ above advice to work w/ your family first (are you a teenager?) Then learn correct watering practices & you won't have gnat issues.

Sand will make your problem much much worse because it holds more water near the surface.

To get rid of the gnats you need to address the issue of excess moisture first such as using gritty mix, emptying your saucers right away, or lifting your pots up so they can dry underneath.

Once you resolve the moisture issue, then you can use BTI to kill the gnat larvae. It comes in a bottle at garden centers. Follow the instructions when you water, repeat for a few weeks, then they should be gone.

Even if you cover the surface with sand and it does prevent gnats from being able to access the soil there to lay their eggs, they will go to the drain holes.

Gnats are going to breed in peat, it just happens. Gnats are a pest of some soils, not the plants themselves. Stressing plants by letting the "soil" become so dry that gnat larvae are killed is going to be impossible if you have quite a few pots. Agree with the suggestion to move toward a more plant- and ecologically-friendly substance with which to fill pots, but the expense of that may prohibit you from being able to stop the problem as immediately if you are unable to change all of the soil now.

The BTi suggested above will get rid of the gnats and prevent them from coming back. I've not heard of the bottled versions, but it sounds great. You can also look for "Mosquito Bits" with the bird items (because it's also perfect for putting in bird baths so mosquito larvae can't live in those, harmless to people, pets, birds, a naturally occurring bacteria, not a manufactured chemical 'cide.) I'm sure both work the same way, put it in your watering can & (when plants are thirsty,) water them with the BTi water, which kills the larvae.

Ah right, mosquito bits and dunks also work. We don't have them readily available here in Canada so the BTI bottle you mix with your watering can is easiest to find.

Let me tell you that gnats will breed in gritty mix! If you try water deprivation your plants will suffer and die first. I have tried it before even in conjunction with 1.5" thick layer of grit on top.

As for sand, it won't stop gnats. Think of the beach where there are even more gnats!

Sand just clogs everything up and stops your mix draining well. All I can say is since I moved to a gritty mix and put my plants outdoors permanently I have not had a single case of fungus gnat - that is 17 years now.

If only we could keep our house plants outside all year. I move mine out in the spring but come Sept.-Oct. I have to bring them in because it gets well below freezing for weeks and months at a time in the winter. I envy your Med climate!

Like SpanishFly, I haven't seen fungus gnats in years since I started using a gritty mix. I also have some epiphytic cactus in a mix of coco chips, Orchiata bark, pumice and a little pro mix hp and haven't had gnats in that either. I do let most of my plants dry out pretty thoroughly (not to the point that they suffer).

Unlike SpanishFly, I'm in New England with no Mediterranean climate; mine are inside from September to late May.

I don't have gnats either, as long as I don't have any peat in pots.

If it was warm enough for my potted plants to be outside all the time, I would just put them in the ground. Tending a pot is much more labor-intensive than letting a plant grow naturally in the ground. The desire to cultivate plants that are not hardy in ones' location is the usual impetus for having "houseplants."

Hmmm - I primarily use the gritty mix,

but use a fair amount of the 5:1:1 mix as well.

I haven't seen a fungus gnat, indoors or outdoors, in many years - other than the cloud that forms above a containerized moss garden I mist at least twice daily. They seem to love that; but, I blame the gnats on the milk I often mix in the spritz water I use and count on to provide N to the moss. I'm not sure what likes the milk more, the moss or the FGs.

Al

Can i just say that some people such as myself use indoor/outdoor gardening for their mental health, wellbeing etc. So whilst im sure the above comments about telling someone to sort their damily problems out first weren’t meant to be abraisive, it quite presumptive and some families are complex. No offence meant at all, I just thought i’d create some awareness. As for the pest issue hun, some pests really hate the smell of certain herbs like lavender, some hate the smell of lemons. Excuse the pun, but do a bit of digging online and you will probably end up buying some more little beauties along the way which can sit with your plants to help deter them. Good luck 😉

Not cool.

Al