Allotments 4 All

I had some lovely big alliums (I think they are Christophii) which I planted approx. 4 years ago. They have not flowered for the last two years, possibly because they are in what has become a very overcrowded spot in my garden. If I dig them up and plant them somewhere else next year, do you think they might revive?If so, when is the best time to lift them?

If you have a few leaves on them I would feed them up a bit with some folia feed then when they have died back putting the goodness back in the bulb, lift them check for damage, then plant in the autumn

They've got loads of leaves, just no flowers. :(

Move the bulbs after they've died back. I've had Christophii fade away on me a time or two, maybe it's not as easy as some of the other alliums.