We just received a question from a reader who is dealing with some worms in her gardening project. She said she has recently started terrariums, which are transparent globe-like containers that are filled with growing plants. She used some plants and soils that she bought from a local nursery, along with some local mosses she harvested. She wrote that she discovered some small white worms in one of the sealed terrariums about two months after constructing it.

She continues, “They don’t seem to be grubs because they are about the same width all the way down their body. They appear to be coming out from the tips of one of the plants, and they are all crawling up the side of the glass. I even found some on the outside of the glass but they were dried up, it seems they can only stay inside where there is condensation.” She is curious if these are harmless or if they should cause her to worry.

Our reader described these worms as being 3-5 mm long, and sent in several photos and even some videos! The videos show that the worms move in a typical worm fashion, and they are very thin and almost translucent white. What could these be?

The photo and description leads us to believe that she is dealing with nematodes. There are over 20,000 species of nematodes, some of which are microscopic, and one handful of soil might contain thousands of these worms! Nematodes are also known as roundworms. Roundworm shouldn’t be confused with ringworm, which is a fungal infection that affects the skin.

Gardeners who make terrariums often spot these little creatures, so our reader shouldn’t get too anxious about the appearance of these worms. Additionally, nematodes are often beneficial to the soil and plants, and only attack other insects.

To summarize, our reader found some small white worms in her terrariums. We believe that these are nematodes, or roundworms, and that they will not harm her plants!