Sew a button? or sow a seed?

sow 1 |sō|
verb (past sowed; past participle sown |sōn| or sowed) [with object]
plant (seed) by scattering it on or in the earth: sow a thin layer of seeds on top.
• plant the seeds of (a plant or crop): the corn had just been sown.
• plant (a piece of land) with seed: the field used to be sown with oats.
• (be sown with) be thickly covered with: we walked through a valley sown with boulders.
• cause to appear or spread: the new policy has sown confusion and doubt.
PHRASES
sow the seeds (or seed) of
do something that will eventually bring about (a particular result, especially a disastrous one): the seeds of dissension had been sown.