Try a row cover, the disappearing broccoli is most likely from cabbage butterfly caterpillars... or snails.

You can start some broccoli seeds indoors now and plant out in late Feb. or early March for a late Spring Harvest.

The other suspect might be birds, some of which love tiny seedlings. Broccoli sprouts are delicious.

I agree with chadinlg, try protecting them with some kind of physical barrier. Broccoli has been easy here, and it should be even better for you with your cooler climate.

I'd suggest using Bt, cabbage worms can be tough to see. I lost my cole crops every year until I controlled the aphids and cabbage loopers that are always around.

Thanks, all. I guess it's physical barriers for me this year.

Flea beetles can also really decimate certain brassicas. In any case, I agree that physical barriers would be a good way to go.

In my cold winter area I direct seed around March and don't get a broccoli harvest until August-September. Add to that the flea beetle damage in the spring and the aphids in late summer, and I've begun to question whether the payback is really worth it. I've grown cauliflower, cabbage, and brussels sprouts as well as broccoli, which were all delicious but had the same pest problems and the long long wait to harvest. Now kale is probably the only cole crop I'll grow each year.

Besides the other things mentioned, mice will mow a row of sproutlings down. While we can technically direct seed brassicas, there is probably too much pest pressure, at least until the rains start. I find that once the rains come pest pressure drops(bugs,birds,rodents, rabbits) but by that time it is too late to direct seed lots of stuff. Our seasonal droughts leave the critters desperate(at least where I live). Transplants are probably the way to go either way, or a little of each. It's always good to back things up so as to not lose an entire season.

Oh yeah, pincher bugs can do serious damage too. It seems like there has to be lots of them and or a shortage of other food. They would be on the seedling munching by 10:00 at night. Not sure if they eat broccoli, I think seedling yes, but they will eat many vegetable plants. They will love living in the nooks and crannies of row cover where it tucks into the dirt.

I tried row covers this fall on napa cabbage. It probably did help prevent the cabbage worms but I was still getting a lot of damage. I went out at night and the slugs and earwigs were having a party under the row cover so I got rid of the cover. The heads did survive but I had huge investations of earwigs, had to throw away much of the outer leaves.