I planted argula several weeks ago and it was growing and looking healthy. I was gone for four days and came home to most of it eaten by some insect (don't think it was deer) as it is now lacy stems. I hate to put insect spray on a green such as this. What do I do?
Vernon County Missouri
Since arugula is in the cabbage family, it is also plagued by all cabbage pests: imported cabbage worm, beet army worm, harlequin bugs and what have you. It could also have been slugs. One or all of those pests got to your arugula. At this point, if you would like to save your arugula you will have to apply an insecticide, if only it were to deal with the large number of eggs that the pest will have deposited on the leaves.
You can use the following organic products:
Bt (controls caterpillars only)
Neem (controls a wide array of insects and eggs)
Spinosad (also controls a wide array of insects)
All are safe to us up to the day of harvest.
For next year, the only way to prevents this is to plant your arugula in an area where you haven't grown anything in the cabbage family earlier that season AND to cover your seeds with insect netting or floating row cover instantly. Even then, the beet army worms may still get at the arugula. Some people will sprinkle diatomaceous earth to try to deter beet army worms and slugs. Good luck!