Was it poetic license or did lilacs bloom by 14 April in 1865? Lilacs may well bloom by mid April in Washington DC where Lincoln was assassinated on that day and where Walt Whitman may have been living. (I think of Whitman as a New Yorker but he worked, I’ve learned, in DC until at least June 1865.) But the lilacs in my New England dooryard are still weeks away from blooming which makes using Whitman’s poem, When lilacs last in the dooryard bloom’d, as a mnemonic device for Lincoln’s death imprecise. For the record, I read Marc Anthony’s “I come not to praise Caesar, but to bury him” soliloquy on the Ides of March and most years I remember Kennedy’s assassination on 22 November — both sufficiently outside the blooming season to come to mind without a flower.

Lilacs in my dooryard budding…

The observation of bloom dates has new importance to me since I have pushed the Rhode Island Wild Plant Society to participate starting this year in citizen science projects related to plant phenology. That lead to my discovery of Richard Primack, a professor of biology at Boston University, who together with colleagues has used Thoreau’s observations of plant pheno phases as recorded in Walden MA to determine that some plants are blooming earlier now than they did in the mid 19th century. Reading Primack’s recent book, Walden Warming: Climate Change comes to Thoreau’s Woods, is also part of my extended practice of remaining horizontal while my foot recovers from surgery.

Lilacs, whether they bloom in April or May, are icons of spring. Elliot used them in The Waste Land (“April is the cruelest month, breeding Lilacs out of the dead land…”), Shakespeare doesn’t mention the lilac but they had just been imported to Europe at the end of the 16th century. In that way that olfactory memories can be so emphatic (the olfactory bulb is part of the limbic system with easy access to the amygdala which plays a role in emotional memories as countless newspaper articles report). I do not smell a lilac without remembering a hedgerow of them, now plowed under in Princeton University’s relentless march to build, between Baker Rink (which must be too solid to tear down) and the tennis courts (gone like the lilacs) where I’d go in the spring just to inhale lilac perfume.

Of Walden’s three spring harbingers, the other two — the drooping arc in the Western night sky of Venus and the warbling song of a Hermit thrush — don’t come close to embodying the nostalgia of the lilac. Whitman may have taken license with the blooming date of lilacs, and maybe he wasn’t a birder. The thrush winters over along the Eastern seaboard as far north as Rhode Island so hearing a thrush does not signal spring to me. Maybe that’s why Whitman leads with the lilac. No matter the seasonal veracity, the first few lines of his poem are enough to connect my April budding lilacs to Lincoln’s assassination for an annual memorial. And I’ll try to report to the correct date on which my lilacs bloom to the citizen science project.