I have a flat of Balsam flowers growing inside that I planted a little over two weeks ago. They are all up and about 4 to 5 inches tall already. They grow like wildfire under growing lamps. I transplanted them outside last year and they took off out-doors as well. I am in zone 6 and they bloom all summer long into early fall. They do reseed themselves by the hundreds! Easy flower to start from seed.