Verbena can be tricky thanks to the hard seed coat. Stratify it first for best results.

But IME it is more about the moisture level and soil temp than covering or not, light or not. I prefer to very lightly cover the seeds with a thin layer of very fine vermiculite (perlite works but you need to grind it fine first). That helps stabilize the moisture level around the seed until it breaks the seed coat.

Dave

Thanks, Dave. Some seeds are so persnickety, it's a wonder that the species is able to propagate!