Ah, the pleasures of the New York Botanical Garden in winter. The crowds thronging to the Holiday Train Show. The deep greens of the hardy conifers.

And, this year, the sweet aroma of flowering viburnum.

Across the region, this uncharacteristically warm winter has flower beds springing to life. Daffodil bulbs in suburban gardens are sending up tender green periscopes. And in city parks, roses are showing their plumage against Christmas tree backdrops.

It is not normal. And while the plants will probably not be harmed in the long run, it may mean a less vivid floral parade in the spring.

“When you smell something that smells like spring now, that’s a little bit unexpected,” said Brian Sullivan, the botanical garden’s vice president for gardens, landscape and outdoor collections. “It’s unusual to smell the fragrance of a viburnum in December.”