17 November 2022

Customer Question – Fungas Gnat Swarms?

Q. “Good Morning. I got your emails from the RHS. I have attached two photos FYI – in my bedroom I have 18 x 3″ pots in which I am growing avocado seeds, and also a 10” pot in which I am growing a lemon tree. Foolishly instead of using houseplant compost I just used generic multi-purpose compost which would be fine in the garden but is a nightmare in the house. As you can see from the second photos I have a massive infestation of fungas gnats which apart from being extremely annoying as they fly around your face, they make a right mess when they die and fall all over the bedding and furniture.

I was recommended to try both cinnamon and cold chamomile tea and put both on the compost as the Sciarid grubs don’t like either, however they have had no effect. I have also read that predatory nematodes will effectively kill all the Sciarid grubs in the compost which in turn will mean the gnats will disappear. Do you sell anything like this please? Hope to hear from you soon and thx in anticipation.” David Grant.

Q. Thanks for the message and wow that is an infestation, which must be very annoying. Yes we do sell nematodes for controlling fugus gnat otherwise known as Sciarid Fly and we normally use a combination of Sciarid Nematodes to kill the larvae (you water them into the pots soaking the compost) and Glue Traps to kill the adults. This combination is normally very effective. The nematodes is £9.99 for a small pack and will more than enough for you pots and you can add a pack of glue traps for £6.99 as well – see below for details :-

I hope this helps Kind regards

Jon @ Green Gardener

Sciarid Fly – Also known as compost fly / fungus gnat, Sciarid fly is a common pest of greenhouse plants and houseplants. The Sciarid flies crawl over the compost surface and if disturbed fly on to the lower leaves – there can be very annoying especially on houseplants. The larval stage in the compost attacks the roots and can kill young seedlings. Control sciarid fly naturally by applying Sciarid Nematodes.

Sciarid Fly Nematodes are safe to use on food crops, safe for children, pets and wildlife and are easy to use – mix the nematodes with water and water directly into the affected pots / trays. Sciarid Fly Nematodes need a daytime soil temperature of 10°C. Safe for plants – will not scorch tender seedlings or young plants. Safe for you – use on plants in your living room or conservatory. Sciarid Nematodes are a living, perishable product (it will keep for up to 2 weeks in the fridge), so please order when the pest is present and you are ready to treat. Available in two sizes – choose between a STANDARD 15 sqm pack or a LARGE 50 sqm pack.

Pot Glue Traps – Use these yellow Pot Glue Traps to monitor and control insect pests such as Sciarid Fly in your pots – perfect for using alongside our Sciarid Fly Nematodes. Supplied in a pack of 5 x DOUBLE SIDED Traps with 2 x 30cm metal holders. The pot traps with holders are perfect for positioning at the base of the plant, near the compost to control Sciarid Fly, while the traps can also be suspended higher up the plant for pests like aphids and whitefly. Insect pests are attracted by the bright colour and become stuck to the trap. They should be changed as they become full up with pests or become dirty. Pot Glue Traps are available in packs of 5 with 2 x 30cm metal holders included.

Available to buy now