The wonderful thing about lilac trees is they're considered low maintenance. My friend tells me to be honest, growing up in Ohio, her mom had a lilac tree out back near the garage and she doesn't remember her doing much with it. It was an established tree so other than cutting blooms for a vase in the house, not too much attention was paid to the tree except in spring.
Lilac trees also are fairly hardy and can tolerate a wide range of growing zones from 3 to 9 and can last for decades in your garden. Dwarf lilac trees generally reach to about 8 feet while larger growing trees may grow upwards of 30 feet.
The best time to plant new or bare root lilac trees? Fall before the ground freezes but always double check with your local garden club or agricultural department before planting a lilac tree or other flowering trees.
When planting your tree, be sure to make the hole deep and wide enough to accommodate the root system including those that are bare root. Lilac trees are even more dramatic when planted in a row but you will need to keep at least 5 feet between the trees to allow room for growth.
Frequent fertilizing is not recommended for lilac trees but fertilizing in spring can help boost blooms. One thing you will want to do though is keep your lilac trees pruned. Trimming should be done with a good pair of clippers and it's best to cut the entire stem. Most lilac tress will not need pruning until they reach about 6 feet tall. The best time to prune the tree is right after they have bloomed for the year.