Q.Companion planting
I live in south central PA. Do you think planting gladiolus and hollyhocks together is a good idea? Will they bloom at the same time? The glads are already established. The plan is to introduce hollyhock plants mingled in with glads.

I think hollyhocks and gladiolas would work well together. Hollyhocks may get a little taller than your gladiolas so you may want to place them towards the back.
They both like sun. The bloom period for hollyhocks is usually June through August. Your glads will flower July through August if you start planting them in mid-May then again every two weeks through mid-June.