Two years ago I planted some giant delphinium in a boarder together with gladiolas and lillies with the view that I should get a good mix of colour from May through to September. This worked well the first year and everything grew well albeit a bit thin.

Last year the delphinium grew very well with plenty of stalks however there was no sign of the gladiolas or lillies which only managed to to grow a few sparce leaves each.

My initial reaction was that the delphinium were starving the over plants of light / food. Given how well the delphinium grew last year I am a bit apprehesive to move them, has anybody any ideas as to how I can encourage the lillies and gladiolas or alternatively suggest something that will grow well with the delphinium?

Any suggestions are greatly appreciated.

Thanks