Tobacco is very hard to grow. Tobacco grows best in frost free season. Soil effects the plant very much. Sandy soil makes the plant light colored, larger, and burns with weak aroma. Better soil causes the plant to grow smaller, darker leaves, and they burn with strong aroma. 

       Different tobacco products contain different types of tobacco. Each year a farm most likely grows different tobacco. Lot's of insects, bacterial, fungal, and viral diseases attack the tobacco, so by rotating the crops, they are unlikely to get these things. Also before planting farmers work a fungicide  into the soil  that controls  fungal diseases  and also controls nematodes, microscopic worms that infest roots. Farmers also use herbicides to control weed and insecticide to control insects.