There probably is not enough nicotine in fresh cut tobacco to do much harm, the leaves need to be cured to concentrate that alkaloid. Nicotine is not considered an accetable organic pesticde any longer.

Around here, the gardeners who grew up in the depression use tobacco in and around their vegetable gardens as a pesticide / maybe barrier. One guy gave me several uprooted plants the other day for the seed. He'll plant it around the edge of his garden with a few plants scattered in and among what he's growing.

I have no idea if it is scientifically sound, but I know half a dozen guys who swear by it.

Whatever these guys use, they call "tobacco", but it sure doesn't look like the commercial varieties I've seen in photographs, - small, maybe 2 " leaves, plants about 2 ft high. Each plant has a dozen or so seed pods about the size of a marble, with a bazillion tiny seeds - it likely is is something else.

What insects are you having problems with?
What veggies are you growing?
What is your soil like?
What fertilizer have you used in the past year?
What else have you used on your garden in the past year?

I have some OG grown tobacco, the only inscet problem was flea beatles.

I have used 1/2 package of chewing tobacco purchased in 1994 to control almost every bug in my garden, Leaving my bene's like bees and dragonflies.

The Jerry Baker formula works well for me, $10 for stuff lasted over 13 years.

Well it really depends on the breed you use, and how you lay out your garden. I breed Virginia, samsun and aztec and the first two acts more like a retribution than a solution. Pests eat other plants, then move onto the tobbacco, then get sick causing them to die or, become slow and disoriented, or leave.

However with aztec tobbacco the insects often die before they realize it is harmful to them. It acts as a wall for Pests that do not target any specific plant. It also is pretty hardy. that being said it's not as pretty or big as other types of tobbacco, will need to be planted around your gardens perimeter, and bug's can simply walk around it. It also isn't good for smoking

You are much better growing aztec tobbacco separately, harvesting the leaves, drying them, and using them to make next years pesticides. This requires far less planning and tobbacco plants

Understanding you would need to steep it like tea and spray it

Is tobacco mosaic virus a concern?