Lilac tree

I have an old lilac tree in my garden which had to be moved last year to make space for construction work. Despite my pleas very little care was taken during the digging up process and it looked pretty sorry for itself by the end of the season. Still, it seems to be budding up now though it's fairly straggly and crowded with lots of little twig-like branches which I'm not sure are live growth. I know that the best time to prune would have been straight after it flowered but I'd really like to ensure this tree's survival (it was from my grandad's garden who is now deceased) so I'm wondering if I should give it a bit of a 'haircut' to give the roots less to support this season. What do you all think?

It's definitely worth it to sacrifice this year's blooms to take some stress off the plant. It takes a lot of energy for the plant to make buds and blooms. You're better off making the plant focus it's energy on its roots. (You should probably even use a root stimulator solution). It would also be a good idea to thin some of the branches out and/or take some height off of the plant. The idea is to balance the root to shoot ratio which ideally should be about equal.

As for the dead vs live branches you could try the following method: choose a branch that you think is alive and grab it in your fist so that you can feel it against your palm. It should feel cool to the touch. Then grab another branch that you believe to be dead the same way. Dead branches should have a more room temperature feel. The logic of this method is that a live branch has water in its "veins" and the water makes it feel cooler. A dead branch is dried up, and without water to cool it down, it feels warmer than the live branch. This method works best on smaller branches with less bark but I find it to be very helpful nonetheless.

Good luck with your lilac. It would be a shame to lose such an heirloom.

You can also scratch the bark just a tiny bit with your fingernail--if the branch is live you should see green underneath the bark, but if it's dead it'll be brown. Also if you wait until spring, you'll be able to see which branches put out leaves and which don't, the ones that don't are likely to be dead.

Thanks guys, as soon as it stops raining I'll get the loppers out!

Hi Nicky, wait till say March/April, we are getting quite a bit of frost and snow forecast this winter and if you go prune your Lilac, then the frost might get into the cut tips and kill of the rest of the branches, the main thing to do as soon as you see new tiny leaf buds is give it a good feed with either fish/bone and blood, or a multi purpose feed for shrubs/roses etc, I take it when you replanted it, you added lots of nice new compost/manure to the soil in the hole where the roots would go, also in spring, if we get the same good hot spring as we did last year, early March/ April (that was our summer he he he) then make sure the plant cant dry out at the roots, it will be in a bit of shock after being ripped out the soil, but Lilacs are normally hardy tough plants and feel sure it will come back, for finding out dead branches from living ones, the method Ecrane gave is the most positive way, sometimes a plant in shock just takes longer for the sap to rise to the tips of each branch, so only prune the bits you have to at first, then after good growth, you can do a harder prune if you still feel you need to, as mentioned though, you may not get good flowers this year but the roots are the most important for this season to keep it growing, it should flower again the following year. Good luck. Weenel.

Ooops, too late! However, I didn't go mad on the lopping, mainly because I couldn't get at most of the tree and I thought it was safer to go easy for now. It's in a fairly protected corner of the garden sheltered on 2 sides by fences and walls so hopefully it'll be okay.