leave my leaves alone.

May 18, 2010 8:49 AM

What are these strange, meandering white lines on leaves in my garden?

I have a mysterious ailment afflicting some plants in my veggie garden. It's mostly on my brassicas but is also on my basil, some beans, a couple tomato plants, etc. The lines are visible on the top of the leaf (here is a darker pic that might be better for you) but there seems to be a blistering on the underside where the lines are the newest. They eat through the leaf on the bottom, leaving a thin tissue-papery membrane of leaf "skin" on the top that is easily ripped (the greyish spots in the pictures). The one time I examined and pulled apart the blistering on a leaf I think I saw one or two small white insects leaving the wound but I can't be sure and I don't want to damage my awesome sprout any more. The plants seem healthy besides this. I've seen cabbage worm but I check every day and squish them as soon as I see them, which has only been 3 or 4 times.

I've sprayed with malathion and insecticidal soap to try getting rid of this but it seems not to work. Bonus question: what is the best least-impact insecticide for my garden? It doesn't have to be organic but it would be nice.

This picture of my bean plant shows these lines more prominently from the top.

Thanks, hive mind.

posted by dozo to Home & Garden (2 answers total)

Best answer: Yes, leaf miners. The easiest way to prevent them is with spun polyester row covers. I grow tons of leafy greens under row covers and they're all picture perfect.
posted by HotToddy at 9:29 AM on May 18, 2010

Response by poster: Thank you, everyone! It does appear to be leaf miners. I'm relieved to see that they're rather benign.

We have been looking at row covers for a while and I think this is the right time to invest. I hate using sprays so a barrier is quite a bit more preferable.

HotToddy, the site you linked to has a great pest and disease identifier!
posted by dozo at 9:43 AM on May 18, 2010 [2 favorites]