Nicotiana sylvestris

 This nicotiana persists in the fall garden

Heavenly scented flowers open in the evening

 Millay as a student at Vassar: Arnold Genthe

I have been growing Nicotiana sylvestris, an heirloom plant, in my garden for the last 15 years. It is also known as 'Only the Lonely' because it grows so tall (4 to 6 feet) that it stands alone as a sight to behold, especially in an all white or moon garden. Clusters of four-inch-long, tubular white trumpet-shaped flowers open in the evening and exude the most heavenly fragrance. Cutting the plant back after the first flushes of bloom in mid- to late-summer will often trigger a second round of flowering, which is the case here, even as many other blooming plants begin to subside in the fall garden. 

Please note: All parts of this plant are poisonous if ingested, hence it is not suitable for planting in a garden where children play. Cats and dogs seem to have no interest in it. However, if you are the least bit concerned, refrain from planting it or grow it in a container that you can place on top of a tall planter or urn. 'Only the Lonely' blooms well in part shade, likes a fertile, moist but well-drained soil and may need staking. Treat it as an annual and save the seeds for planting the following year as this tender perennial will not survive a frost. In Zones 5 and 6 it can easily be grown from surface-sown seed in mid-spring.

 The National Gardening Bureau named  2009 the Year of the Nicotiana and 'Only the Lonely' was touted as one of the most fragrant flowering tobacco cultivars: 

 "In Victorian times, Nicotiana sylvestris was planted along walkways and paths so that those strolling by could enjoy the sweet fragrance of the flowers.

 "Noted garden writer of the early 20th century Louise Beebe Wilder described nicotiana as a "poor figure by day ... but with the coming of the night the long creamy tubes freshen and expand and give forth their rich perfume and we are then glad we have so much of it..." The poet Edna St. Vincent Millay wrote, 'Where at dusk the dumb white nicotine awakes and utters her fragrance in a garden sleeping.'

 "It appears that nicotiana fell out of favor with many gardeners because the tall plants often needed to be staked or supported to keep them looking nice in the garden. Today there is renewed interest and appreciation of both the heirloom species and modern hybrids as nicotianas find a home in contemporary gardens."