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How to Plant a Lilac Tree

By Amy Hannaford ; Updated September 21, 2017
Lilac tree

Lilacs are known for their intoxicating fragrance and cone-shaped clusters of small blooms ranging in color from deep purple to pink, blue or white. Blooms appear from mid-spring through summer, making them a favorite of gardeners. Lilacs can reach heights up to 20 feet and need several weeks of cold temperatures to induce flowering.

Choose a location with at least five to six hours of full sun. Plant in early April to early May or wait until late September to early October. Avoid planting along walls or near other trees.

Prepare the soil by adding a handful of lime to create a more alkaline soil. Mix it in well and, if needed, add compost to ensure good drainage.

Dig a hole twice the width and depth of the root ball. Place the lilac in the hole so that the top of the root ball is even with the ground surface. Backfill the hole, tamping down the dirt as you go to be sure there are no air pockets. If planting more than one lilac, space them about 10 feet apart to allow for growth.

Water the plant well after planting. Water once or twice a week for the first month or so after planting to get established; after that lilacs do not need to be watered more than once or twice a month since they are drought resistant.

Apply a 3-inch layer of mulch, such as bark, from the main trunk just to the outer most branches. This helps to conserve moisture in the soil and keeps the soil cool in the summer months.

Fertilize with an all-purpose fertilizer every spring and again immediately after the last flowering. Add a handful of lime twice a year to the top of the soil to keep your lilac in peak condition.

Deadhead and trim dead branches to ensure active blooming and to keep your lilac shaped. In the fall after the final flowering, cut back a quarter of the branches since lilacs bloom on new wood. New plants bloom in two to three years. After that, they may bloom for years, with some lilacs growing to be over 100 years old.


Things You Will Need

  • Lime
  • Fertilizer
  • Mulch

About the Author


Amy Hannaford teaches childbirth education classes and a healthy pregnancy series in Southern Oregon. Hannaford holds an Associate of Arts degree, a certificate in medical assisting, and has been a childbirth educator and birth doula for 20 years. She has been writing articles for Demand Media since 2008.