Greetings!

This spring, we alerted you three days prior to when your lilacs were predicted to leaf and bloom, an effort we call springcasting. Our hope was that these predictions would help you to more accurately capture the start of leafing and flowering on your lilacs.

Below, we compare your reports of leafing and flowering from Nature's Notebook with our leafing and flowering predictions from the Spring Indices.

We've added a new aspect of spring to our suite of spring maps - the end of spring! We will forecast the activity of plants that bloom at the end of the season. This information will help us understand the length of the spring season in a particular year, such as whether a location that sees an early start to spring also sees an early end. Check back on on our Status of Spring page next year to see how the end of spring unfolds.

We hope that you will join us again next year to report leafing and flowering on your lilacs. Each year that you report adds to a dataset over 60 years in the making and helps us to understand the impact of climate and other factors on plant phenology. Thank you for contributing to this important project!

What you reported this year

This year, you reported leafing for 67 cloned lilacs and 123 common lilacs.

How do your reports compare to our predictions of leafing from the Spring Indices?



Our predictions and your reports are not far off! On average, you reported leafing of cloned lilacs one day later and common lilacs two days earlier than we predicted this event would occur. You reported leafing for 75% of your cloned lilacs and 45% of your common lilacs within one week of our predicted date.

This year, you reported flowering for 58 cloned lilacs and 97 common lilacs.

How do your reports compare to our predictions of flowering from the Spring Indices?

Again, our predictions and your reports are not far off! On average, you reported blooming of cloned lilacs four days earlier and common lilacs one day later than we predicted this event would occur. You reported blooming for 62% of your cloned lilacs and 63% of your common lilacs within one week of our predicted date.

Your reports of lilac leafing and flowering help to improve the Spring Leaf and Bloom Indices, which are used as an indicator of the start of spring. Knowing when plants will undergo phenological changes has value to agriculture, human health, wildland management, and more. We hope that you will join us again next year to help us continue to ground-truth these predictions of leaf out and flowering in lilacs.

Thank you for continuing this important legacy!

Contact

Erin Posthumus

erin@usanpn.org

520-314-7883

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