I forgot to mention Ranuculus.

Those don't go directly in the ground. They get started early in pots inside, then get planted out after all danger of frost with the tomatoes. If they aren't started early, they'll decide to bloom around the end of August or so, just about the time they'll start getting unhappy with the cold weather.

I'm going to plant my dalhia bulbs next week, It will take a while for them to break ground. I bought new lily bulbs, started them in the house last month. They were up about 4 inches, I planted them last weekend and they are doing good. All my other bulbs that were planted over the last few years are up several inches so I think the new ones will be fine. I planted rac. toes a couple months ago inside, but will wait until it warms up before outside planting. You should be safe to plant the lily bulbs outside now, a friend of mine planted hers outside last month. Good luck!!

My mail lady says she planted her Dahlia bulbs this past weekend, so I'm probably going to do mine today. This is at least her second year having them in the yard and she planted hers at the advice of another avid gardener, so I feel safe putting mine in too.
Mad Gallica, were you referring to Rannuculus?

No, what I've had experience with is dahlias, begonias, and enough canna to cover NY state. It's the same idea as relatively slow, hot weather annuals. Planted outside directly, they move too slowly to make much progress here until too late to put on a show. I learned that big time when I picked up some started dahlia tubers and unstarted ones at the Ct plant swap. Most people there are much warmer than I am, and start things a few weeks earlier. It makes a big difference in the performance during the summer.