How can I properly care for an old lilac bush in my garden to ensure it continues to thrive and bloom beautifully?

To care for an old lilac bush, prune it regularly to remove dead branches and promote new growth. Provide adequate sunlight, water, and nutrients, such as fertilizer, to support its health. Mulch around the base of the bush to retain moisture and control weeds. Additionally, consider transplanting the bush to a sunnier location if it is not thriving in its current spot.