Asked July 3, 2013, 3:30 PM EDT

My Swiss chard has some kind of liitle worms in the leaves. It is ruining my crop. What can I do?

Multnomah County Oregon fruits and vegetables insect issues

1 Response

You have happily feeding larva of the spinach (or beet or chard) leaf miner. The adult fly lays it's eggs on the leaf and they hatch and burrow into the juicy bits between the upper and lower leaf surfaces. You can often see them if you look carefully. Sometimes, they will have completed their life cycle and left their frass (aka poop) behind. The leaf sections they don't eat are ediible after trimming. The best non-chemical protection involves putting floating row covers over the seeds or young transplants as you plant them and leave the cover in place to exclude the insect as the leaves grow. Just make sure there is enough slack to allow the leaves to push the fabric up. Some people make hoops for the fabric. Picking and destroying the partially or completely damaged leaves (eat what you can) will reduce problems. There are several organic insecticides that are labeled for use on spinach leaf miner. Always read and follow all label instructions. Chip

Chip Bubl
OSU Extension/Columbia County
503 397-3462