Weston's Spring Rainbow LILAC

 Every May Weston’s Spring Rainbow lilac reliably produces striking new growth shoots in tones of bronze, yellow, orange and pink, creating a unique color splash for several weeks. As its flowers open the bright foliage colors start to fade, and as its single blue flowers finish their bloom, the leaves become “normal” green for the remainder of the summer. The flowers are typical for the species in size, color and form, creating a distinct contrast with the foliage until they are in full bloom. The original plant, along with all those we’ve propagated, has never produced suckers.

It was Mike, our Weston Nurseries field supervisor in the 1980’s, who first spotted this unique lilac cultivar. It was a chance seedling growing among a population of several hundred Common Lilac (Syringa vulgaris) we’d propagated from seed and planted in our "Busconi" field, block 57I. Only about three feet tall, it was a distinct oddity in the field so early in the spring. Initially we thought it might be exhibiting herbicide damage. But after observing it for several years, we realized that its unique new growth coloration continued to be stable each year.

We rooted a few cuttings in the 1990’s but never added it to our main propagation line. In 2005 we recognized that this plant deserved to be more widely used, and registered the cultivar with the International Lilac Society:

"Syringa vulgaris L. ‘Weston's Rainbow’ was registered 15 August 2005, by R. Wayne
Mezitt of Weston Nurseries Inc., 25 Phipps Street, Hopkinton, Massachusetts 01748. The
original plant was selected from seedlings of unknown parentage in 1997; initial vegetative
propagation took place in 1999. New growth is a distinctive red-bronze, changing within a few
days to bronze-gold and then yellow chartreuse as the flowers begin to open. During the
flowering period the color of the foliage changes to the usual green for the remainder of the
growing season. Thyrses are on average 20 cm long and 15 cm wide; usually there are two
thyrses per flowering branch. The florets are 1 cm in diameter; the tubes 1 cm long; the corolla
lobes are flat; the floret color is in the Violet Group (Royal Horticultural Society, 1966). At ten
yeas of age the original plant is about 2.70 m tall and 2.40 m wide. Hardy at least to USDA Zone
5, but not yet tested elsewhere. A Standard Portfolio has been opened at Royal Botanical Gardens
Herbarium, Hamilton, Ontario, Canada, (Acronym: HAM) but is not yet completed.
Literature Cited: Royal Horticultural Society. 1966. R.H.S. colour chart. Royal Hort. Soc., U.K. "

Around 1999 I asked Roger Coggeshall and Evie King at Syringa Plus to propagate Weston’s Spring Rainbow lilac for us. They succeeded in producing some plants, but were not able to get it into full production. Finally in 2017 we were able to  successfully propagate it using tissue culture.