prune dwarf koren lilic

I have a 10 year old well established dwarf Korean lilac. I would like to cut it back, how far back can I go?

 

Hi Ewsmith,

Prune up to one third of the oldest stems to the ground. Do not prune each stem to a desired length or you will have all kinds of sprouts from the cut and it will look unsightly.
http://homes.mainetoday.com/gardening/050522tomcol.shtml
http://www.ipm.iastate.edu/ipm/hortnews/1993/2-10-1993/lilac.html

Newt

 

Don't do it now tho' - wait til late Oct. when it's dormant, or late winter/early spring.

 

As per the instructions at the second link, wait until late winter or early spring, especially in your cold zone. Cutting it back in October could lead to dieback due to heavy frost.

Newt