A favorite of many gardeners, the lovely, sweet-smelling lilac is often planted by the back door, so the family can enjoy its scent just as they step out to the backyard. While not a particularly fickle plant, the lilac does need the right kind of care for it to flourish.
The lilac is related to the olive and can grow between 12 and 20 feet tall, with a spread of 8 to 14 feet. Its branches are thick with flowers in the spring, and the flowers can be white, purple, yellow or deep red can grow in 10 inch long clusters. Even the big, heart-shaped leaves are attractive when the flowers fade. Old shrubs are tough enough to serve as supports for flowering vines such as clematis. The lilac attracts butterflies and hummingbirds and can tolerate rabbits and deer.
Lilacs can grow in nearly any type of soil as long as it is not waterlogged. However, it prefers rich, fertile, well-drained soil that is either neutral or more on the alkaline side. This means a pH of 7.0 or a little higher. If the soil is a bit too acidic, it can be amended by adding lime. A gardener can find out the composition of their soil by sending a sample to their nearest cooperative extension. A report not only lets the gardener know the soil’s pH but the levels of nutrients such as calcium, nitrogen and phosphorus.
A lilac bush needs at least six hours of sun a day for glorious bloom, though some can flourish in dappled shade. They do best in hardiness zones 3 to 7.
Lilacs can be grown from seeds that are sown in early spring right after the date of the last frost. They are best grown from cuttings from green wood, old wood or the roots. Some lilacs are grown by budding or grafting. The easiest way to grow a lilac is to buy one from a nursery. These plants can come in containers or in burlap.
Dig a hole about 18 inches deep and wide. Some gardeners add a handful of fertilizer, but make sure this is covered with soil before adding the plant so not to burn the roots. Mound some soil in the center, and spread the roots of a container grown plant over it. If the roots are in burlap, gently cut away the burlap. Make sure that there are no roots encircling the ball, and cut away roots that look dried up or dead. It’s best to place the plant about 3 inches deeper than it was in the pot. Fill the hole in, water, tamp down the soil with hands to fill in air pockets then water thoroughly again.
Place the plants at least five feet apart. One good idea is to plant lilacs with different bloom times so that the garden has a display of lilac blossoms for most of the growing season.
Add mulch to keep the soil hydrated, keep the roots cool and discourage weeds. The mulch shouldn’t touch the crown of the plant, which is where the stem connects to the root. Water the plant about twice a week until it is established.
— Dave Miller (@cozycrates) June 7, 2022
Once it’s established, the lilac doesn’t need special care, but it should be pruned immediately after flowering. Older, larger plants can tolerate hard pruning.