why aren't my delphinium growing?

[BarkingUpTheWrongRoseBush]

Got delphinium plug plants delivered - they've been sitting potted on to slightly bigger pots since the spring. And they aren't doing anything. They look healthy but small. I gave them a bit of feed and a repot to see if that would help. But I thought they would have bulked up and been ready to go in the ground by now. Am I being impatient?

I’ve been impatient and put mine in the ground, they’re healthy and alive but not really doing much.

I'm 12 months ahead of you. I put a tiny one in last year and it did flower but only max about 30cm. This year it has two flower spikes and is about a 70cm-meter tall. I've put some more in this year and they haven't flowered. I wish I'd kept them potted and in the greenhouse. Will know for next time.

I planted one last year and it’s really small although is flowering. Others have not come up at all and were great last summer. I thought it was just me not being very good with them.

This is my first year of trying to plant things like this, I’ve always done annuals and veggies or mature plants, it didn’t occur to me they would prefer some time in a pot, they are healthy and will just have to hope it’s a favourable winter.