This is one of the easiest-to-germinate plants I've ever grown. It sprouts easily in tough soils, in heat, in cold, in sun, and in shade. They sprout in about three to five days. The seeds are large.
I highly recommend these for school projects (as are done with sunflowers in cups). The plants are much shorter than sunflowers.
These ones took four or five days to sprout. They began sprouting in large numbers yesterday. This picture was taken this evening on the day when it was supposed to get to 103° F. I supposed it did; I wasn't monitoring it constantly, but it was 100° F. the first time I checked.
There are more safflower plants (which sprouted today) by the chicory, in a much more shaded area.