Summer Flare® Japanese Tree Lilac - Syringa reticulata 'SumDak' (RFM-78)


Japanese Lilac

A tall, upright Japanese tree lilac growing in a nontypical form for the species. The stiffly ascending branches above a substantial trunk combine to create a tree lilac much narrower in form and greater in height than cultivars or seedling grown plants generally found in the landscape. Large creamy white flower panicles in late June, good foliage quality, and prominent bark lenticels add to its ornamental features.


USDA hardiness zones 3 - 6

Mature Size

Height: 30 - 35'; Spread: 14 - 16'

Form (Shape)

Narrowly oval to upright

Growth Rate



  • Summer: Bright green
  • Autumn: Insignificant




Large terminally borne panicles, creamy white in color and consisting of many small perfect, fragrant flowers. Flowering occurs in late June after foliage formation and persists for several weeks.


Tan capsules in large panicles that persist through winter adding to seasonal interest

Light Preferences

Full sun

Soil Preferences

Moderately drought tolerant, prefers moist well-drained soil. Soil adaptable even to alkaline soils. Will tolerate dry soils once established. Intolerant of wet and flooded soils.


Budding and grafting, cuttings and tissue culture

Ornamental Attributes

The desirable upright growth form, showy flowers, summer foliage quality, and bronze gray bark create an attractive large Japanese tree lilac for urban planting

Landscape Attributes

Recommended for use as a boulevard, landscape, public grounds, parks, schools, and golf course tree where a large tree form Japanese tree lilac can be used to diversify tree species use


Consideration can be given in street side plantings as an upright, stress tolerant tree for urban planting

Patent Status

U.S. Trademark registered - Summer Flare™

Licensing Status

This cultivar is available for non-exclusive licensing


Grafting and budding materials available for trial


Download the PDF Datasheet (PDF, 320.93 KB)

Inquire about this technology >