has any one had any luck growing them from sprigs? was told that you just threw the cut stems on the ground and covered litly with soil . well has not worked! do lilacs produce a toxin that will not alow them to sprout ? trying to get some growing over the old farm "dump"were they used to grow,well still grow just not in this area. have tryed the layer method else were with similar results. area grows grass and weeds fine!other than cat litter and wood ash nothing"dumped" since 1945!