We haven’t had the best luck starting seedlings this year. In January, Matthew planted cruciferous veggies. They germinated decently, looked healthy for awhile, and then bit the dust. We noticed lots of little gnats around the grow trays and thought they might have been transmitting some kind of fungus.
We moved on to warm weather crops (tomatoes and peppers). Guess what? The gnats returned! I investigated and we most likely have fungus gnats. The gnats lay eggs in the soil, which hatch into larva. The larvae consider the tender roots of seedlings a delicacy item.
I instituted remediation steps immediately after identifying the problem on Monday.
Step one: Stop the over-watering (ahem, honey) and let the soil dry out. The gnats and their larvae love really damp soil.
Step two: Work to eliminate the gnats. There are a few suggestions for this, including shallow dishes of beer or sticky traps (made with petroleum jelly). We tried both. Finally, a good use for beer!
Step three: Get rid of the larvae. This one is trickier. One place suggested putting potato slices on top of the soil to attract the larvae. We tried this overnight and didn’t see anything in the morning. That could mean that 1) the larvae weren’t there; 2) the larvae do not like potatoes; or 3) the eggs are in the soil waiting to hatch.
We started a RIDICULOUS number of tomatoes, most of which are looking pretty good at this point, and I’ll be really upset if we lose them like we lost broccoli, cabbage, and cauliflower!
Info on fungus gnats and how to get rid of them: