I have had good luck with bees on cotton. there are pros and cons to cotton It produces a lot of nectar. The plant blooms in stages providing an extended flow. the honey crystalizes quickly. There have been reports that the neonicatoids leach out in the morning dew killing bees. Cotton is one of the most sprayed crops grown. I have been told they will only work the flower when it is white to yellow when it turns purple they will not work it.