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:
Good timing with this post. My indoor herb garden has been struggling, and now I think I know why!
I have that same green planter. Did you have to cut more drainage holes?
Love the blog!
As an update, one of the other issues with the tomatoes might be lack of nutrients. They grew so much, in a short period of time, in a relatively small amount of soil, that they might be a little starved. We are doing some very minimal fertilizing (1/4 or 1/5 strength) to see if that helps. This may be useful for potted herbs and potted plants in general. The nice thing about fertilizing potted plants (compared to those planted in the yard)? You don’t have to worry about fertilizer run-off contaminating waterways.
We have not made any modifications to the green planter on the right side of the picture. I don’t even know if you can detach the bottom to drill more drainage holes, but it might be worth investigating.