I have not been successful in propagating lilacs with both kinds of layering,
1. ground layering and air layering
3. cuttings, and
4. grafting.
1 & 2 I did ground and air layerings for quite some time; after about 2 years there were still no roots. Lots of info on the web.
3. Cuttings never rooted. I understand commercial growers propagate lilacs with cuttings, but they use expensive mist setups. You might try the following. It looks thorough:
https://sites.psu.edu/corinnes...
4. I used the side by side grafting of two lilacs where both plants were well rooted in the ground. The graft just didn’t take. If you have a privet hedge, you might want to root a piece of privet. It roots more easily than lilac and is a close relative to lilac. Once the privet is rooted, graft a piece of the desired lilac onto it.
5. Some lilacs produce suckers which grow out of the ground and have roots. I dig a bit around each one carefully. If I feel it is sufficiently supplied with roots, I pot it up and put it into the shade and water well. Months later it can be put anywhere, even into the ground if in the right season. If, when I dig around each sucker, I do not find enough roots, I cut through the "umbilical cord" between the parent lilac and the sucker. Then I leave it alone for another year to grow more roots.
6. I have not done the following, but it is generally a good way to grow sprouts. Remember : pruning encourages growth. I know how you’d hate to hurt your favorite lilac, but there is a type of propagation called stump. Look it up under stump, mound, or stool propagation. You cut to within inches of the earth and stand back. You’ve probably seen an overgrown tree that’s been cut down, but the stump sends up sprouts up in no time. Here is a web site to get some stump information:
http://www.fao.org/docrep/006/... Cut your lilac in that manner, but let’s do a couple things differently. I would add an aluminum collar which you fill with soil. Etiolation means depriving of light. Etiolation also causes the area deprived of light to be pale and causes the cells to be more likely to produce roots. The soil you put into the collar does the etiolation for you. If you can get the May/June 1988 issue of Fine Gardening pp. 43-45, there is a fine article on etiolation.
7. Then there is tissue culture (tc) which is quite another matter. Here's a free tc protocol for syringa (lilac).
https://sites.psu.edu/corinnes...
Some protocols are for sale; others are free. Look for them with the genus plus words like in vitro, micropropagation, or tissue culture.
Order or borrow from your library Plants from Test Tubes: an Introduction to Micropropagation by Kleyn & Kyte It also is a source of protocols for many genera.
Tissue culture can extend gardening to a year-long hobby.
Good luck fiwit, if you’re still there. 3Pete
