Good question. I would guess yes since my older ones are up in the garden already, but i have no idea about new sprouts. I've been covering everything with a tarp just in case, but I'm not brave enough to have planted out anything but lettuce and other cole veggies in our zone. Last frost date is still a month away.

They will be fine.---

Don't worry-Be happy.

I've planted a bunch of seedlings last weekend, including rudbeckias. We had two nights with frost. Just checked all my "babies", all are doing fine. I even planted some Tithonia and they survived (mostly, some got hit). But that was quite protected spot. Last weekend, I have planted already a lot. I'm not trying to beat any records. This weather mixed everything. I should be be planting first weeks of May. But everything is growing so fast and getting out of containers. In the second week of April, I have three trips, so I'm thinking, at least if I'll put most of the plants into the groung before, they'll have a better chance to survive then in overcrowded containers. I'm not going to plant zinnias or cosmos, or other very sensitive ones. I hope, I can trust my DH to take care of a few containers, but, definitevely, I can not trust him with all. So, I'm sitting now and checking all sites with weather... there will be again a few nights this week with low 30s. Therefore, to plant or not to plant, this is a question....

Yes.

I would place tithonia in the same category as zins.