Lilac trees, also known as lilac bushes, remain old-time favorite gardening plants offering profusions of fragrant blossoms in late spring. Lilacs require cold winters in order to bloom each spring, making it an ideal bush for the northern states. It might take a few years for a newly planted lilac to bloom the first time. But once it starts, with proper care, the bush may keep blooming for generations to come.
The first lilac bushes were planted by early settlers in the mid 1700s. One of the oldest plantings may be found at the Governor Wentworth estate in Portsmouth, New Hampshire. Now lilac bushes grow across the country with some reaching more than 100 years old. One of the oldest and largest collections of lilacs may be found at the Arnold Arboretum at Harvard University. Some of the lilacs planted around 1806 still thrive on the Arboretum's grounds.
Lilac bushes require a period of cold weather to produce blooms in the spring, making them ideal for hardiness zones 3 to 7. These deciduous plants range in size from dwarf-sized trees reaching five feet or less in height to bushes growing to 30 feet tall. Each spring, the tree sports a profusion of highly fragrant white, pink or purple clusters of blossoms. Once the blossoms fade, the light green foliage adds nice texture to any garden.
Twenty-four species of lilacs exist with two originating from Europe and the others coming from Asia. Gardeners may choose from more than 1,000 varieties and hybrids. Two favorites, Miss Kim and Palibin, remain popular choices for today's garden. Miss Kim is known for its compact shape and fragrant late blooms that thrive in warmer climates while Palibin features a neat growth habit with plenty of blooms in the spring.
Lilacs thrive in sunny locations as long as the soil is well-drained. Lilacs do not grow well in soils with drainage problems. To counteract this problem, amend the soil before planting, or the bush needs to be planted in a raised bed with proper soil. To retain moisture around the roots, several inches of mulch should be added. The new plants require regular watering along with extra water during the hottest days of summer and well as in times of drought.
Lilacs require no pruning until after they bloom for the first time. Once the bush stops blooming, it's time to prune it since the bushes form the buds for next year's blooms during the summer. Remove any dead wood.