When you plant seeds in the ground, you sow them. You can also sow things like doubts or ideas, simply by spreading them around. If your ideas (or your seeds) develop and grow, you've successfully sown them.
The verb sow is pronounced completely differently from the noun sow, which means "a female pig." When you sow flower seeds, it rhymes with "go." When you admire an enormous, muddy sow in a pig pen, it rhymes with "cow." When two words are spelled the same but sound different, they're called heteronyms.