I'm in Zone 6a, last frost May 7th.
First time growing dahlias.
I planted two varieties in the same area, identical conditions, good soil, lots of sun on May 13.
One came up in 10 days, the second came up in 15 days.
It has now been almost 6 weeks with no sign of life from the other two. I careful poked around a bit and from what i peeked at the tubers look healthy and firm. They have not rotted from what I could see without disturbing them.
Can it really take more than six weeks to sprout?