Lilacs (Syringa)

Published On: February 29th, 2024


The sweet fragrance of Lilac flowers is a scent beloved by almost everyone. Science has shown that our sense of smell is more closely related to our brain’s emotional center than any of our other senses. This explains why fragrances can produce such powerful emotional responses and carry us back in time with vivid memories of the past. So…. let the aroma of lilac blossoms transport you back to spring days in Grandma’s Garden. And create new olfactory memories for your children and grandchildren by planting a Lilac in your home landscape!


Old Fashioned Favorites

The Common Purple Lilac (Syringa vulgaris) and its cultivars are old fashioned favorites, treasured for their vintage charm. There are many heritage varieties still available in the trade that have maintained their popularity through the generations. These include such favorites as the intensely fragrant double blooming ‘Beauty of Moscow’ (1947) and the showy bicolor ‘Sensation’ (1938).

While full of nostalgic appeal, classic Syringa vulgaris has its limitations as a landscape plant. It tends to grow quite tall and a bit rangy, and the flowers are often restricted to the top third of the plant. It is also susceptible to Powdery Mildew during humid summer weather which, while not usually harmful to the plant, can be unsightly.

Newer Introductions

Newer hybrid introductions offer the classic large clusters of exceptionally fragrant flowers combined with vigorous, modern-day disease resistant foliage and slightly more compact habit. The fresh green foliage of the Scentara ™ and New Age™ series resists disease and keeps the plant looking good even when it’s not in bloom.


Dwarf Lilacs

The Dwarf Lilacs (S. meyeri, patula, and hybrids), with their dense, compact growth habit, are ideal for foundation plantings. Their smaller leaves are highly disease resistant and turn wine red in fall. The flower clusters are smaller than those of S. vulgaris but are produced in profusion and completely cover the plant when in full bloom. Size has been bred down to as low as 3’ mature height on some newer varieties.


Lilacs bloom on “old wood”, or growth put on in the previous season. As such, they should be pruned immediately after flowering in late spring/early summer. Pruning done later in the season will remove the flower buds for the next spring.

Older varieties that are prone to Powdery Mildew can benefit from a preventative fungicidal spray routine


Lilac Trees

There are two types of Lilac Trees:

Japanese Tree Lilac (S. reticulata) is a small landscape tree with an oval habit, growing to a height of 25’. It bears creamy white flowers in June, several weeks later than shrub form Lilacs. The flowers are aromatic but have a distinctly different fragrance from traditional Lilacs.

Lilac Patio Trees aren’t actually trees at all, but rather dwarf lilac shrubs that are grafted on a single stem standard to grow in a tree-like form. The standards are typically about 5’ tall and the shrub atop the standard will put on additional growth, bringing the full height to 8’-10’. The head should be kept pruned to retain the dense lollipop-like appearance.

Lilac in a Nutshell:

  • Mature height: 3’ to 15’, depending on variety
  • Mature spread: 3’ to 10’, depending on variety
  • Growth form: Loose & upright to dense & compact, depending on variety
  • USDA Hardiness Zone: 3
  • Flowers: Clusters of exquisitely fragrant flowers in a range of colors, depending on variety.
  • Foliage: Green foliage. Red fall color on some dwarf varieties.
  • Light requirement: Full Sun to Light Shade
  • Water Requirements: Tolerant of a range of soil conditions. Drought tolerant once established.
  • Growth Rate: Moderate
  • Maintenance: Prune immediately after flowers. Older varieties that are prone to Powdery Mildew can benefit from a preventative fungicidal spray routine.
  • Especially valuable for:

 Exquisitely fragrant flowers
 Mixed shrub borders & deciduous screening (taller varieties)
 Foundation plantings (dwarf varieties)
 Deer resistance
 Nostalgia

By Zannah Crowe