Good question! You know, most large branches have enough stored food in them to survive, bloom, and even leaf out, long after being cut or snapped off the main tree.

That being said, I doubt your big thick stem could or would re-root for you, BUT you could try taking some cuttings from the smaller pencil-thick stem sections and plant them in the ground, and/or also put them in water and bring them indoors for "forcing" where they will still bloom and often leaf out indoors.

Because lilacs like to reproduce themselves so much, when I force them indoors, a small subset of the branches usually forms roots which can be planted outside after a couple of weeks. Forsythia and some others do the same.

It's a bit of a long shot, but it's worth a try, and hey, if nothing else, you can force some indoor blooms from the stems for an indoor bouquet. I'd cut some and stick them in the ground and cut some to stick in water indoors and hope for the best. If it doesn't work, you'll have indoor blooms, and it certainly won't make any babies if you don't try.

Keep us posted on what, if anything, you try, and how it works out. Sorry for the damage by the way. Ugh!

Take care,
Grant

I vote to get rid of it, due to it's size.

I've seen tree limbs 6" in diameter or larger, removed, and still develop buds and some leaves for a while.

Hey - I did not know you could force lilacs! Can you force hydrangeas as well? I ask because my mom was diagnosed with terminal cancer a month ago and loves lilacs and deep blue hydrangeas. Could I force these so she could have a bouquet? If so, when do I take the cuttings to do so?

Thanks in advance.

You need to be much closer to the bloom time to have success with forcing. Lilacs bloom here generally late April to early May, so you could attempt this around the beginning of April. Flower buds need to be present and swelling.

I've never heard of anyone with success forcing hydrangeas, but I would imagine it could be done. You are looking at mid-June probably at the earliest for these. You might be better off just buying your mom a florist's hydrangea in full bloom at the nursery or (often) the grocery store. These are forced into bloom out of season under greenhouse conditions. And after she enjoys the flowers, you can gradually transition it into a planting for your own garden.

Oh yeah, you can easily force lilacs. Like GG said, closer to the bloom time is definitely better (I usually start mine in mid April) but it's worth a try for Alathia's branch since it's already broken off. Honestly, it might have enough stored energy in it for the stems to continue to progress "normally" outside and then take the cuttings in early April or so.

Of course, if it was my big broken branch (er, if it was my LILAC's big broken branch), I'd try some now, and then some in several weeks. Good to experiment and you never know, the earlier ones may just root, but for my own healthy lilac's stems, I force them in April.

There are tons of spring flowering shrubs that you can force indoors; generally just harvesting them a few to several weeks before their normal bloom time is the best time to get them started. I force forsythias, flowering quince (both now), lilacs (April), flowering currants (now), early-blooming fruit trees (have some plums blooming inside right now). I haven't tried or heard of people forcing hydrangeas, but you never know. Even things like Japanese maples are fun to force early (I'll start some in a week or so).

Take care,
Grant

I replanted a lilac bush...Seemed to do fine for a couple of weeks, but now is starting to wilt...I added miracle grow, but doesn't seem to liven up....what do I need to do to save this bush....It is in sunny and part shade