Lilac graft.
By Telme8
Vale of Glamorgan,
Wales 
I have a lovely double white lilac, which has flowered poorly this last year or two. Last year I noticed one branch had purple lilac flowers on it, so obviously the stock root is taking over from the Graft , which explains its performance. If I cut the root stock growth off as near to the base of the graft as possable, will the white lilac pick up or would I be wasting my time and better to dig it up and replace it.
19 May, 2009
Answers
Thanks Mims, I thought so but was not sure as to how resiliant the white would be, but at least it is worth a try.
Thanks again, just want the wind and rain to stop to get at it, as the flowers have gone over so would be a good time to attack!
19 May, 2009
do as mims says and the white growth should perk up.
19 May, 2009
Thanks both do or die,
19 May, 2009
Previous question
« it started to grow in April is now 3ft tall long leaves 6 inches flower heads
Yes, take the aberrant growth off right at the root stock - you will have to be watchful and continue to remove the ones you don't want when they grow. Hopefully the grafted plant will do better if you're vigilant, but the reason, asyou probably know, that it's grafted is that the rootstock they've used is much more vigorous than the plant grafted into it.
19 May, 2009