I would say go for the glads- not sure about the others. The first year I planted them at this house I staggered them well into May maybe even June and got blooms all summer and into fall. So, they didn't all fizzle at once.

Liatrus is a perennial so I don't think it matters when you plant them. However, I'm not sure they will bloom this year.

Freesia do not do well in hot weather. Here a fall planting works best. They will return every year blooming about April. Al