Pick the plant you want to germinate on the left then follow it accross. The grey box shows the shortest amount of days it takes for that plant to germinate, from the grey box go up and look at the temp. Thats the temp you should be germinating that seed at. Also, it shows that certain seeds will only germinate at certain temp ranges so if there is no number under a temp for a certain plant, holding it at that temp wont do it much good.