Lilac trees are drought-resistant plants that typically require pruning and a sunny location to thrive in temperate regions. A small amount of compost can be used to promote growth.
HGTV recommends planting lilacs in an area where there are at least six hours of full sunlight daily to encourage healthy growth. Lilacs do not require regular watering and prefer well-drained soil that is rich in nutrients. The Old Farmer's Almanac recommends placing a layer of compost topped with mulch around the base of the tree each spring to hold in moisture and provide necessary nutrients.
Pruning lilacs is one of the more important aspects of care to promote bloom production. Using a sharp knife or scissors to remove each bloom after it withers ensures new blooms appear on the lilac tree. HGTV recommends removing a portion of the tree's branches during June by cutting back about one-third of its flowering branches. The upper sections of the tree can be cut back as well, if the tree is too tall, by cutting the branch off at eye level. Additionally, removing two of the larger branches by sawing off at the base of the tree produces more aggressive blooming during the next spring.
If the lilac tree isn't blooming, adding fertilizer is not recommended because some products may reduce or eliminate the tree's flowers. If necessary, small amounts of fertilizer can be added once during winter to protect blooms.
Lilac trees are hardy shrubs that are easy to grow and can live for hundreds of years when properly maintained. Powdery mildew is one of the most common diseases to affect the lilac. Plant lilacs either in the spring or fall, although later plantings are often preferable. Container-grown plants are easy to transport from the nursery to the soil.