Yesterday, when I watered my plants, a small cloud of minute black insects ascended, reminding me of a scene from a Harry Potter movie. If you have those black things hovering ‘round your plants, see fungus gnats below. Healthy houseplants usually don’t have problems with insects, but I don’t know a single indoor gardener who hasn’t had problems, so feel no angst. A good organic potting soil, the proper amount of light and water, and regular feedings with a good liquid houseplant food will go a long way toward keeping your plants healthy. NOTE: Winter is resting time for plants, so don’t fertilize then. Check new plants for insects before…