I planted many nasturtium seeds here in Portland during some warm weather in early March. Some have germinated, but I suspect many won't since I think I jumped the gun and the seeds drowned or froze as a result. Anyway, it's going to be in the 70s this weekend but is expected to cool to 62 degrees by Thursday. Should I hold off on planting zinnia and sunflower seeds or can I get going on that tomorrow?