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I recently bought some succulents and replanted them in a cactus mix (does contain some sphagnum peat moss)mixed with pumice. 50/50 mix. Now I am noticing little flies hovering around the plants and congregating on the soil.

IS there anyway to get the infestation under control without repotting?

What if I let the soil dry out totally. Put a 1/2 to 1 inch layer of fine sand on top. While putting it some yellow traps? Do you think this will work?

If not, what other potting medium do you reccomend. I don’t live near a nursery and it takes me an hour by bus to get to one.So I would prefer not having to repot.

Drought Smart Plants reply:

These annoying little flies are fungus gnats – the adults do little more than simply fly in your face and go up your nose when you water, but meanwhile, the young are doing damage to your plants roots.

All your solutions are sound – drying out the soil completely for a few weeks will certainly help – this is the primary reason that you have an issue. The adults will find rotting organic matter and permanently moist soil very attractive to lay their eggs in, so drying it out will prevent this, as well as being better for your succulents, which will rot in moist soil.

The sticky traps are an excellent idea. Keep in mind that new adults will be constantly hatching out, so keep replacing the sticky traps until they are completely gone. The best sticky traps are yellow for fungus gnats.

I wouldn’t use fine sand for mulching, as this can clog up the pore space of the soil even more. See if you can screen some fine gravel, getting rid of the fine sand and dust. My favorite mulching material for succulents is lava rock, which is similar to the pumice in your cactus soil. Sieving that might give you a workable option, if the pumice is not too small.

Whatever you do, don’t give up – fungus gnats are persistent, so you have to be more so. Don’t turn your back on them!

Eventually, you might want to find a different potting mix (this could be where the fungus gnats originated) and you can sterilize it with boiling water poured through it to kill off any eggs or pests.

Good luck with this – I know how frustrating and difficult these little insects can be.