|Several of my potted plants have fungus gnats. I have used certain nematodes to get rid of them in the past. Where can I purchase these.|
|Predatory nematodes are sold under a variety of names including Orcon and Fungus Gnat Predators (Hypoaspis sp.) by Greenlight. Large, well staffed local nurseries, Home Depot and Lowe's should carry them. Or, they are available online from Gardener's Supply and Nature's Control websites.
There are several strategies for controlling fungus gnats. They breed in moist potting soil, so you can break the breeding cycle by allowing the surface of the soil to dry out. If you have plants that need moist soil simply place a quick draining and fast drying layer of gravel or sand on top of the potting soil. This will act as a barrier to the soil. Or, you can drape plastic wrap over the soil (cut a slit so you can place it close to the stems of your plant, then overlap the cut ends so the pests cannot find a way to the potting soil). You have to be a little patient with this method because you have to wait through the next generation's maturation before they are gone for good. In other words, once the generation now already in the soil become adults and die off without being able to reproduce, there should be no more gnats. Another method is to use a product called Gnatrol as a soil drench, another is to use an insecticidal soap as a soil drench. Of course, always follow the label instructions carefully. I hope this helps!