I was preparing to direct sow some seeds in the garden yesterday before the storm when I got the idea to make a short seed starting tip video. This garden video explains seed scarification and how to use this seed-starting technique to germinate seeds with tough seed coats.
If you're curious, a couple of years ago I made a post on the mrbrownthumb garden blog on seed scarification, stratification and soaking that is a little more thorough than this video. But the above video should give you some insight into germinating seeds that have tough seed coats.
Do you have seeds that give you a hard time?