It means about the same thing as "plant." The writer just used a synonym for variety. The writer wasn't trying to suggest any difference in meaning. Both just mean to suggest an idea, to spark an idea. Someone says "A" and that gives someone else the idea "B."
They both mean to put a seed into the ground, and I realize I'm not 100% sure what the technical difference is. I thought I knew, but I checked a dictionary for sure, and I was right. "To plant" means to place an individual seed into the ground, probably in a little hole. "To sew" means to scatter lots of seeds over the ground--probably ground that's been prepared or softened--and let them fall where they may. Your writer isn't trying to suggest any difference, though.
The famous painting, "The Sower," by Jean-François Millet, is the perfect illustration of the verb "to sow." You even see the seeds falling through the air.