Knowledgebase
Saint Cloud County Road 137 Visual Barrier Hedge Planned for 2022 #780636
Asked January 22, 2022, 4:06 PM EST
Stearns County Minnesota
Expert Response
Lilacs prefer full sun and moist, well-drained soil. Try to avoid wet soils with poor drainage. The soil should be pH 7.0 to slightly alkaline. Have your soil tested by the U of M Soil Testing Lab. Do not fertilize when planting. Water the shrubs during the first season so that they can establish a large root system. It is generally not necessary to fertilize lilacs. However, lilacs can be lightly fertilized in early spring every few years. Heavy fertilization may promote excessive vegetative growth and discourage flowering. The soil testing lab will tell you what fertilizer the soil requires. Your spacing may be too close.Space multiple lilac bushes 5 to 15 feet apart, depending on the variety. Many French lilacs should be planted 10-15 feet apart. The planting width should be based on the mature size of the shrubs. Cultivars of the common or French hybrid lilac (Syringa vulgaris) often do not bloom for several (five or more) years after planting. Apply a 2- to 3-inch layer of mulch around each shrub to conserve soil moisture and control weeds. Water lilacs during dry weather.The best time to prune lilacs is immediately after flowering in spring. Common lilac usually doesn’t bloom for several years after planting, other species of lilacs bloom when quite small. The dwarf Korean lilac (Syringa meyeri), ‘Miss Kim’ lilac (Syringa patula ‘Miss Kim’) and Preston lilacs (Syringa x prestoniae) often flower within one or two years of planting.
https://extension.umn.edu/yard-and-garden-news/lilac-issues-season