New Red Robin trees dying

[madmaz50]

Planted 7 x Red Robin 12' standard trees in April. They all seemed OK when planted and for the next 2-3 months. They all then 'flowered', but some then lost nearly all of their leaves and have now gone black at the ends, with no new leaves. I have fertilised them with 'Vitax Q4', but it hasn't done any good. I am afraid they are dying.
Are they dying and if so what can I do to save them ?

[Robinia]

What's your soil like? Have they been waterlogged this summer (or very unlikely, have they dried out)? You might need to improve your drainage. Don't overfeed them and see if they recover in the autumn.