Location

• Lilacs should be planted in an area with full sun. Space them 10 to 15 feet apart. If planting lilac as a hedge, decrease the space between plantings to 6 feet. The Chinese lilac is the best variety for hedge plantings. All lilac trees prefer well-drained, loamy soil with a pH between 6.5 and 7.0. To achieve the desired pH, amend the soil with ground limestone. If these requirements are met, lilacs will thrive even with minimal fertilizer in subsequent years.
  
  

Planting

• Plant lilacs in the early spring, when the tree is dormant. Place established trees in a large hole with plenty of room for root spread. Situate the tree so it is no more than 1 inch lower than its original planting. Add a small amount of aged manure or organic compost to amend heavy clay soils and improve drainage. Fertilizer is not necessary during the first year. If desired, add a slow-release 18-6-12 fertilizer about one month after planting. Use about 2 oz. of this fertilizer per 4 square feet.
  
  

Care

• Established lilac trees should be fertilized in the early spring before growth has begun. Use a balanced fertilizer such as 5-10-10, 10-10-10 or 20-20-20. Use about 1/2 lb. of fertilizer for each 25 square feet. Soil pH should be tested every three or four years to maintain proper levels. Lilac trees require only minimal watering and can typically survive with adequate rain water, requiring special care only in periods of drought. Organic mulch, such as pine bark around the base of the plant, will help retain moisture and prevent weeds.
  
  

Flowering

• Over-fertilization can be problem with lilac trees. Do not to apply too much nitrogen, as this will encourage leaf growth at the expense of the lilac's fragrant flowers. Limit pruning to dead or diseased woods, and remove active flowers only minimally to improve the shape of the tree. A 10-10-10 liquid fertilizer can be used after pruning to help encourage additional growth.