Will soapy water stop butterfly larvae from eating my broccolli plants

Question

my plants are smothered with eggs from the cabbage white butterflies. Ive tried to squash the eggs but as quick as i do that there is more. I have to go away for a few days and dont want to come back to bare stalks

Answer 1

Soapy water will deter the larvae for a while but the moths will come back and lay more eggs.  I used Sevin on my cabbages and the stuf really works.  It's the only pesticide I use in my garden.

Answer 2

It will help. I use washing up liquid in my spray. Regards. h

Answer 3

No, it won't. Soapy water is best used for aphids like green and black fly. Your best bet is to use netting. Also, check the undersides of leaves regularly for eggs and squash them.

A regular spraying with nettle tea, nettles soaked in water for a few weeks, will deter cabbage whites too.

Oh, don't forget to pick the caterpillers off too.

Answer 4

Insecticidal soap works only on contact with the insects.  Once the soap dries on the plant, it has no effect on insects.  It also works best on hard-shelled insects, like beetles and earwigs.

Go to your local garden center and look for an organic insecticide called Bt, or Bacillus thuringiensis.  Bt is a naturally occuring bacteria that is harmful only to caterpillars.  Apply the Bt to your plants and it will kill the caterpillars on your broccoli.  

Broccoli can also be grown under a floating row cover, effectively blocking out the butterflies.  But the broccoli must be covered when it is still early in the season, before the butterflies find it.  Once they start laying eggs, it's too late.  At that point you need the Bt.

Answer 5

the best thing to do is make a frame with fine netting over it