Bloom Dates

Lilacs, etched vases, 2024, for the Project Space at Olfactory Art Keller, New York, NY

Bloom Dates features the fragrance of freshly cut lilacs, including those from my own yard. This evanescent fragrance dominated the Project Room throughout the 3-week lilac season, after which the flowers were allowed to wilt in place, with the fragrance and visual appearance of the piece changing over the remaining weeks of the show.

Data collected since the 1950s shows how lilac bloom dates are shifting across the US. As reported by the EPA “Because of their close connection with climate, the timing of phenological events (i.e. the timing of a periodic biological phenomenon in relation to climatic conditions) can be used as an indicator of the sensitivity of ecological processes to climate change. Two particularly useful indicators of the timing of spring events are the first leaf dates and the first bloom dates of lilacs and honeysuckles, which have an easily monitored flowering season, a relatively high survival rate, and a large geographic distribution.”

I made the connection between lilacs and climate change when I found a bloom-date map (Schwartz M.D., 2021) that utilizes this data to compare bloom dates across the country over the 10 year periods 1951-1960 versus 2011-2020. [If you view the page, click on “Figure 3. Change in First Bloom Date”] Versions of this map are engraved on several of the vases used to hold the lilacs for the show. The data behind this map points to one way that climate change is having immediate effects on ecosystems throughout the country. But it’s not just about plants coming to life in the spring. As summarized on Budburst: “If plants bloom too early for insects to pollinate them, then the seeds won’t grow. And if the insects are too late to gather food from the flowers, they will not survive, either. Without seeds or insects to eat, the mice may not survive. And animals that eat mice, like snakes and hawks, will also go hungry.”

Budburst is a great resource for community scientists, gardeners, and anyone looking for historical data on pollination and phenology. They also forecast the dates of each year’s phenological events. Data on my own lilac shrub is available here. Budburst aggregates data from observers across the country. You can search by date range, location and/or plant type.

Budburst is free to use and it’s easy to add your own data, which I would encourage you to do!

Installation video

Thanks to:
Eric Nadler at JCFabLab for laser etching vases
Wei Chen Chao for lighting and photography assistance
Lewisboro Garden Club for access to more lilacs than I have in my yard