Is the sumac in za'atar the same as the tree growing in my front yard (eastern Ontario) - i.e. can I take the red fuzzy things off that tree and grind them up with the other ingredients to make my own za'atar??
You're talking about Lebanese Zaatar which is red and made with sumac. Everything Lebanese is very very different then the rest of Arabic cuisine - being Palestinian, I enjoy Lebanese cooking, but I prefer traditional Arabic food.
If you want to purchase a good Palestinian version of Zaatar head over to Nassar's where you can buy the proper blend of thyme, thyme, oregano, marjoram, with toasted sesame seeds, and salt.
Get a good olive oil and dip your bread in it with the zaatar.
It's so unbelievably good!