Lilac tree and bush

chemblue

Happy and Peaceful New Year. Hope you are keeping well and keeping safe. 

I have a lilac tree and lilac bush they are at least 20 years old. I have attached photos. Should I leave them alone the tree has little flowers high above we pruned it after it flowered this year but now as you can see looks an odd shape I would like to cut it right down and rejuvenate it. What advice would you give. I want to do the same to the bush. 

Any advice would be appreciated 

Obelixx

Lilacs flower on wood produced the previous year so the time for formative pruning is immediately after flowering.  I suggest that in March you give both the tree and the shrub a generous dollop of slow release fertiliser such as blood, fish and bone or rose fertiliser.   You could also give them both a mulch of ell-rotted garden compost or manure any time between now and March on a day when the ground is not frozen.

This will give a boost to both plants for  better growth and flowering.

When you do prune, remember the rule of the 3 Ds and first cut out dead, diseased or damaged stems back to their base.   Then you can prune further stems to improve the shape.  make sure your secateurs/loppers/pruning saw are clean and sharp before you start to minimise tearing and infection to newly cut wood.