I buy starts from a local feed and seed store. I use dipel dust(bt) to keep the cabbage worms at bay. I also kill the cabbage butterflies whenever I see them sometimes a dozen a day. I did just pull up almost all the plants as seconds arent worth the hassel in the spring. In fall/winter I let them put out seconds and thirds. The dipel dust has been allot more successful than any liquid bt I have tried and its easier to keep and deploy.

Fertilome (10859) Dipel Dust Biological Insecticide (4 lb.) https://www.amazon.com/dp/B0056QY572/ref=cm_sw_r_apan_i_QHP8NST6RVRE4K773C5A?_encoding=UTF8&psc=1

Chapin International 5000 Rose & Plant Duster Hand Sprayer, 16-Ounce, Translucent Yellow https://www.amazon.com/dp/B0009KM2LG/ref=cm_sw_r_apan_i_BZDY23Y5HJ67B00NPNHD?_encoding=UTF8&psc=1

for vine borer and other chewers you might Get some dipel dust and an applicator. Reapply as it comes off or after heavy rains.
Fertilome (10859) Dipel Dust Biological Insecticide (4 lb.) https://www.amazon.com/dp/B0056QY572/ref=cm\_sw\_r\_apan\_i\_RZFMC5MNFEN4YEFRBMET?\_encoding=UTF8&psc=1
Chapin International 5000 Rose & Plant Duster Hand Sprayer, 16-Ounce, Translucent Yellow https://www.amazon.com/dp/B0009KM2LG/ref=cm\_sw\_r\_apan\_i\_EEDYW2KYFDARBGYWW1H6