over wintering plants - Knowledgebase Question

Bettendorf, Ia
Question by phillips1
August 20, 2009
When I bring in plants this fall, is it best to use and oil spray or a systemic to kill any bugs living on the plants? I had a terrible problem with gnat-like flies last winter. I washed the plants and used a mild detergent only. What's the easiest and most effective routine?

What's the easiest to use plant medium for a moth orchid?

Answer from NGA
August 20, 2009


It's alway a good idea to thoroughly rinse plants off before bringing them indoors for the winter. I don't think the gnats came in on the plants but arrived through a door or open window. Fungus gnats live and 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!

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:



[ Join now ]

Today's site banner is by Marilyn and is called "Crocosmia 'Lucifer'"