Cause: Caused by a the spinach leaf miner. The fly emerges in spring, mates and lays eggs on the spinach leaves (as below). They eventually drop from the leaves into the soil to pupate - creating the next generation. There can be several generations each year.
Control: Stop the adults reaching the spinach by using covers. Keep the area weed-free. Rotate spinach, chard, and beet crops. Try using a Neem based spray which acts as a repellant and also slows the leafminers' ability to feed, interrupting the cycle. Advice on making neem spray can be found here - I don't know of its effectiveness.
How interesting! If not slightly annoying if you are trying to grow spinach. If you sprayed using this neem stuff could you still class it as organic?
ReplyDeleteluckily the spinach has grown rapidly this year, so it wasn't too bad. I don't know about the organic thing, if it's something you're interested in then I'm sure Google will know :)
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