My delphiniums won't flower

Evening all.
I've just joined tonight so please be gentle.
I bought some delphiniums last year, open root in a bag. 7 in all. I planted them well spaced but not too far apart so when they grew it would make a nice display. They grew about a metre last year and only one flowered. 2 or 3 little blooms. I was expecting this as they would still be establishing themselves, and I thought this year they would look lovely. Nope!.
They have all grown. One had black ditch so I cut it out and burned it. The other are all about 5 feet tall, look really healthy, quite large leaves about 4 inches across. But as yet not even a sign of any heads, let alone flowers.
They are semi shaded, staked, well drained and protected from the wind. I've fed them on Fish bone a couple of times this year. Right or wrong I'm not sure.
Can anyone throw any light on it. I'm a bit baffled!
Really looking forward to getting involved on here. I've been gardening for a few years now. I love it. Not very good, but I love it hehe!
I look forward to some great answered and loads of help.
Thanks in advance.
Ian
Posts
Probably need more sunshine-hours per day ; try moving them when the time is right .
Like Paul said they do prefer full sun.
I would cut down on the fish blood and bone, one application at the beginning of the season is good enough and a feed after flowering, you can get a second flush of flowers if cut to the ground just before the flowers finish. You maybe unintentionally over feeding them which normally encourage leaf growth at the expense of flowers.