|Would like to know how to care for this tree year around?
|Lilacs are relatively low maintenance plants. They would appreciate a top dressing of compost or well rotted manure in mid spring and late fall, along with possibly a bit of complete granular fertilizer such as 10-10-10 in early spring according to the label instructions.
A year round organic mulch several inches thick is also a good idea, apply it over the root zone but not up against the stems.
Pruning can be delayed for at least several years after planting -- possibly longer than that because this is a particularly slow growing type of lilac.
Eventually the plant will become overgrown and thick. Then begin a regular routine of removing a small proportion of the oldest stems each year by cutting them off at the ground in the early spring. This will encourage additional growth from the roots. This plant blooms on old wood, so do not shear it or prune the tips of the plant during the summer or fall as this will remove blooming wood for the following spring.
Some gardeners will routinely deadhead their lilacs, meaning remove the flowers once they have faded, but in my experience it is not strictly necessary to do so.
Enjoy your Miss Kim!