Pine trees dying

Asked September 7, 2017, 2:03 PM EDT

I have been trying to grow various species of pine trees from seed over the last couple months. I have been planting them in tubes and I have domes on them. Anyways many of them sprouted and grow to 2-3 inches tall to the height of the dome) but then would fall over and die. I am wondering what I am doing wrong. I use store bought potting soil. One thing I have noticed is there tends to be a lot of "fruit fly looking bugs" that hang around in the dome. Could this be causing the problem?

Chisago County Minnesota horticulture pine

1 Response

The seedlings may be dying because their stems are being damaged by fungus. When this happens the condition is called "damping off." Go to the following website to learn about damping off and how to prevent it.
https://www.extension.umn.edu/garden/yard-garden/diseases/damping-off/

High humidity and soil moisture favor damping off. Removing the domes (covers) as soon as the seedlings emerge may help.

The insects you mention might be fungus gnats. The larvae usually feed on organic matter in potting soil, but they sometimes damage tender new roots, and as the bulletin notes, fungus gnats may also transmit the fungal pathogens that cause damping off.

If you use sterile potting media, gnats, eggs or larvae will not be present.