I have about 30 potted plants. Some were outdoors for the summer and are now indoors. There are an increasing number of gnats around the soil and flying around the apartment. I have two trays with vinegar and sugar which helps to attract and catch a few, but not enough. Once in a while I will spray bug killer over the plants, but is probably the wrong kind. How do I better control the spread of gnats? Or do I need to replace all the soil?
Certified GKH Gardening Expert
Replacing the soil is one option. Another is cutting back on the watering. Damp soil will attract fungus gnats. They won't survive in dry soil. Here is more: