I've had my indoor garden doing quite nicely until a few weeks ago, when I noticed black specks on my onion stalks. Around the specks, the stalk would dry out, and it spread until the whole thing was covered in tiny black specks and the entire onion plant was dry and shriveled.
They are still green (very pale), no brown spots, and the bulbs look fine and white, but have all shrunk considerably.
The gnats have been getting out of control in my garden area, and when I was examining one of the onion stalks I noticed hundreds of tiny insects that are nearly invisible and pale yellow running up and down the stalks.
Could these be what are causing the onions to do this? And how do I stop them? I've already treated all my pots with an organic pesticide/fungicide spray and it doesn't seem to be helping.