Well, if you aren't opposed to chemicals, Sevin is a relatively safe chemical solution to use when you are far enough away from harvest, just wash your harvest when you pick it.

Organic control methods include BT powder, a bacterial byproduct not unlike penicillin which can be found at most competent garden centers, but it IS expensive.

I try as hard as I can to be organic, but when there is a gun to my head, and I have a choice between critters and my hard fought produce, I'll choose to save the produce.

choosing to use a garden chemical can be a tough decision to make, But I do think that garden chemicals have their place, if used sparingly, and only in emergencies. Usually you will only need an application or two for sufficient control of the pest, and next year you can take all the organic precautions that you need.

I know I am going to be skewered by many on here that chemicals are evil, and they will get no disagreement from me. However in certain situations you really are forced to choose between three very unsavory options:

1) mechanical control, picking them by hand
2) using an organic control like soap water or BT powder
3) resorting to using a farm/garden chemical control in the organophosphate family, which may hurt the beneficial insects, yet provide control to an incredible degree, allowing you to keep some of your fruit.

You can also use floating row covers if you don't want to use chemicals. I only grew broccoli once, those cabbage worms are pretty gross.

BT really takes care of them! I had them last year and one application pretty much took them out. I wont use sevin on the veg, and try not to use it anywhere anything else will work. Its pretty noxious stuff.

Just google cabbage moth BT - I have to buy it online since I am in a small town.

I believe those are cabbage loopers - they feed on other plants besides the cabbage family. I use liquid BT -- 1 TB per gallon of water. I don't like to use dusts because it is too easy for me to get covered in it! Good luck ...

Spinosad. It's the first cousin of BT, and useful for a broader range of pests -- important in Florida where you see some real srange-o's. It's the only pesticide I keep around. Most garden centers have it, I know I've seen the Monterey brand in box stores.

Thanks for all your helpful tips! I do TRY and do organic, but when nothing else seemed to work I did use sevin, one of the problems I did notice was it seems to be a contact killer only and if I have to use chemical I would like to make worth it. I did look up the BT, looks like home depot sells something called Safer brand garden dust, this brand also had a liquid form called 3-1 Garden spray, this is what the description says:
32 fl. oz. concentrate
Contains potassium salts of fatty acids (12.38%) and sulfur (6.48%) as active ingredients
Targets and kills aphids, beetles (Leaf-feeding), caterpillars (Leaf-feeding), crickets, earwigs, lace bugs, leafhoppers, mealybugs, mites, plant bugs, scale crawlers, thrips and whiteflies
Controls and kills powdery mildew, black spot, leaf spot, rust
3-in-1 Concentrate works as a fungicide, an insecticide and a miticide
OMRI listed and compliant for use in organic gardening
Can be used up until the day of harvest
Avoid spraying plants when they are in full sun
MFG Brand Name : Safer Brand

Would you anyone suggest this? I want to make sure I do this right thanks again for all your help!

Not only BT works well, it has permanently reduced the cabbage moth population in my area. Gardeners are popping up all over the place, but I am the only one growing large amounts of brassica.

How often do you need to apply that concentrate, and at what rate? Can you afford to pay for the chemical if you have to apply it daily or every other day, or whatever the rate is.

If it says it works on your pests, and it's not going to break the bank, try it.