Question:  When is a good time to bring the lotus plants outside in the spring?

Answer:  If you don’t mind hauling them in and out, you can do so now. Pull them out into warm sunny area but back inside with temps below 40-50ish. The key to getting them started is heat, so they are almost better off inside steady temps with water than outside with big swings in temps. Once they break dormancy and start growing, however, out in the full sun they should go with a night here or there inside if it gets cool. If you do it that way, and want to put them in the pond, wait until pond water is 70 or they will go back into dormancy again.