I'll be visiting Kew on May 9. Will the famous lilacs be in bloom at that time?
I don't know about Kew, but botanical gardens in the US now often have current information on their websites on what is in bloom and/or expected to bloom soon. So you might want to check Kew's website.
It's been an unusually wet and warm winter so normal bloom times may be different this year. I know windsor great park has blooms earlier this year than predicted.
Don't know about Kew but the lilacs in our own gardens in London are just about to bloom now and in more sheltered spots than my area may well be already in bloom right now. Will they last till May 9. They may just be coming to an end . Hopefully you will just catch the last of them.Edited: 14 April 2014, 09:17
Everything has been 3 weeks to a month early this year with us 15 miles from Kew
As my neighbour's lilacs are in bud now and I'm well north of Kew I think the best of the lilacs will have been before your visit, though as they have a wide range of most species there may well be some in flower. IIRC when I last visited there was a notice/blackboard at the entrance with names of the plants then in a "starring role". There will be plenty of interest!
Here's a non answer. Have you heard of or been to Isabella Plantation in Richmond Park - not so far from Kew Gardens. In early May you should see azelias and rhodis in bloom and the trees just coming into leaf.
No lilac though.