This year, we have been seeing spring conditions for leaf out and bloom occurring earlier than average (the period from 1991-2020) in the southeastern United States, and later than usual in the Southwest. In some areas, this kind of early or late activity has never been seen in the 40 year record, and Washington DC's iconic cherry trees may hit the earliest peak on record.

Early spring conditions can have major consequences to plants, animals, and people. If plants get the environmental cues to start leafing out or blooming too early, then they could experience what is known as a false spring, when temperatures are warmer than average and last longer than usual before winter is actually over. 

The part of a plant that develops these leaves and flowers is extremely vulnerable to cold, so if these plants start blooming during an unusually warm period, and then are hit with more typical cold winter events, it can be really devastating to them. These events can impact animal phenology as well.

People can also be affected by early spring conditions - earlier and longer springs can cause an earlier and longer lasting allergy season, which could negatively affect the lives of over 50 million people who suffer from seasonal allergies in the US. 

The harm that occurs to plants by a false spring can cause significant damage to many crop species, which then causes detrimental economic impacts to both farmers and consumers. 

You can follow the spread of spring leaf and bloom on our Status of Spring page.

Follow along with the Status of Spring »

A group of USA-NPN collaborators recently used over 4,000 Nature’s Notebook observations of oak (Quercus) trees in the eastern US to explore the relationship between flowering and air pollen. By finding a link between temperature and open flowers, they were able to predict peak in flowering timing at pollen monitoring stations. The peak flowering timing was strongly correlated with the observed peak airborne pollen at the stations, demonstrating that volunteer-collected phenology observations can support better predictions of the timing and severity of allergy season. 

Learn more »

Through a collaboration with the US Geological Survey, the USA-NPN has released a Pheno Forecast indicating when red brome (Bromus rubens) flowers and senesces. This information can support grazing rotations as well as estimations of wildfire risk. We are inviting input on this forecast via a one-time brome reporting form that includes phenological stages for both red brome and cheatgrass.

Learn more »

With the help of our student Ariana Ortega, we are bringing new life to the USA-NPN Instagram account! Follow us for campaign news and updates, Local Phenology Program Highlights, and tips for identifying key phenophases in your plants and animals. We love seeing pictures of your observations - feel free to mention us with your spring updates!

Follow @usa_npn »

Human-caused climate change could impact respiratory health, including asthma and allergies, through temperature-driven increases in airborne pollen. Researchers measured pollen trends across North America from 1990 to 2018 and found increases in pollen concentrations and longer pollen seasons. Their results indicated that human-caused climate change has already worsened North American pollen seasons, and climate-driven pollen trends are likely to further exacerbate respiratory health impacts in coming decades.

Read More»

Resting buds transitioning out of dormancy - which buds are which? What are the cues? When do I start reporting?The cues for a plant’s transition from dormancy to renewed activity can be subtle, yet can be quite visible if you are watching closely. It may take careful sleuthing—and sometimes previous experience—to detect the early stages. The tightly clasping bud scales of the dormant buds—or tightly packed leaves of naked buds—begin to shift or ever-so-slightly "swell" and may also shift color. These signals suggest that reporting on "Breaking leaf buds" and "Flowers and flower buds" is not long off.

Learn more »

We're kicking off a new national Nature's Notebook data collection campaign: Pollen Trackers! The data you collect on flowering and pollen release in allergenic plants will help researchers create better forecasts of allergy season.

Join our Kickoff Training Webinar to learn how you can get involved by creating a site in Nature's Notebook and adding one or more Pollen Trackers species. You'll also hear from researchers behind this campaign about how your data will be used.



Register now »

Just four inches long and very active, Lucy’s Warblers (Leiothlypis luciae) have been known in the past as Mesquite Warblers due to their close ties to these trees. With 4 years of data collected, Tucson Audubon has developed a nest box that is ideal for providing nesting space for this species.

They are now looking for volunteers to help us learn more about the relationship between Lucy’s Warblers and mesquite trees. Join this virtual event to learn how to participate in this project.

Register now »