Skip to main content
Shopping Cart
HomePhenology: Tracking Change

Gardening in Changing Times
Phenology: Tracking Change

Contributed by Priscilla Touhey, Master Gardener and Kerry Lake, Master Gardener

What is Phenology? Phenology is the study of the effects of weather and climate on periodic biological phenomena such as plant and animal life cycles. It includes the study of the impact of changing weather patterns on garden plants and animals, especially insects.  Weather is the day-to-day happenings in the outside world and climate is the long term study of the weather that has occurred over decades and even centuries in order to study fluctuations and track trends.

The word phenology comes from two Greek words, one that means ‘to show, to bring to light, and make to appear’ and the other ‘study, discourse, and reasoning’. Historically phenology has been focused on recording the dates of first occurrence such as the reappearance of migratory birds, or the date when forsythia and other plants open their flower and leaf buds, or the first appearance of specific insects. 

In ecology, the term phenology is used to indicate the time frame for seasonal biological phenomena. For example, not only the study of emergence but also tracking throughout the summer and fall of different varieties of insects. Dr. Robert Gegear, from Worcester Polytechnic Institute, gave a presentation at a recent WMMGA continuing education event. He refers to his 20 year study of bumble bees as ‘eco-phenology’. Even small fluctuations in weather impact the time of emergence of different bumble bee varieties but also what plants are blooming at that time and throughout the season to provide nectar for these pollinators until winter.

Why is Phenology Important?

We can use information from phenological sites to enhance our own gardening practices. For example, UMass website at "Compile and record environmental and phenological data for locations throughout Massachusetts to aid in the monitoring of plant and pest development, the planning of management strategies, and the creation of site-specific records for future reference. Detailed reports from Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features."
Specifically, you may be using the UMass soil temperature and Growing Degree Days (GDD) weather-based indicators, for determining the time to begin planting your garden, as a head’s up on the emergence of insects in the spring, or as a measurement of heat accumulation to predict harvest times.

Scientists and their citizen-scientists (the ‘scouts’ at UMass) have been collecting data on weather, plants, and animals for many years. You may have been keeping a gardening journal, but this additional information from phenological websites gives a broader view of the changes that have happened in our ecosystems over a longer period of time, and can help any of us in our gardening endeavors.

Recently, some phenological sites have released data that shows a decrease in insects globally. This impacts not only our agriculture base but also our entire ecosystems. Again, studying the habitats and life cycles of different species of insects may give us an understanding of their demise, but also a better understanding of what may have changed in their habitats. Phenological sites have also documented the lengthening of the growing season over the last century in most parts of the world. Parts of England and Europe are now 19 to 20 days longer; eastern North America is averaging 7 days. Tracking of weather, temperature, plant growth, and animals not only gives us a deeper understanding of our changing eco-environment but the knowledge to garden wiser in these changing times.


Where do we find this type of Information? Here is a selection of some websites, including how You can become a Citizen Scientist:


USA National Phenology Network -

The USA National Phenology Network (USA-NPN) was established in 2007 to collect, store and share phenology data and information and bring together citizen scientists, government agencies, non-profit groups, educators, and students of all ages to monitor the impact of climate change on plants and animals in the United States.

USA-NPN consists of a National Coordinating Office (NCO), located at the University of Arizona, thousands of volunteer observers and many partners, including research scientists, resource managers, educators, and policy-makers. Anyone who participates in their national phenology database, Nature’s Notebook, or collaborates with NCO staff to advance the science of phenology or to inform decisions is part of the USA-NPN.

Nature’s Notebook is a national program of enthusiastic amateur citizen scientists (could be you!) and professionals who regularly record observations of plant and animal life stages in their own backyard.  These observations inform scientific discovery and decision making.  Here is the link for how to participate in Nature’s Notebook by becoming an observer:


Community Collaborative Rain, Hail, and Snow Network (COCORAHS)  is a grassroots, non-profit, community-based network of volunteers of all ages and backgrounds working together across America who measure and map precipitation (rain, hail and snow) right in their own backyard using low cost 4” diameter, high capacity rain gauge to report daily observations on the COCORAHS website.  On-line training is provided.  Started at Colorado State University in 1998, it has participants across all 50 states, Canada and the Bahamas. Each time a rain, hail or snow storm crosses your area, volunteers take measurements of precipitation from as many locations as possible.  COCORAHS’ aim is to provide the highest quality data for natural resource, education and research applications. 

CoCoRaHS is used by a wide variety of organizations and individuals including the National Weather Service, hydrologists, emergency managers, city utilities (water supply, water conservation, storm water), insurance adjusters, USDA, engineers, mosquito control, ranchers and farmers, and more. 

They offer a guide for Master Gardeners created in conjunction with the National Oceanic and Atmospheric Association (NOAA) and its Department of Education. The National Science Foundation is also a major sponsor. MG Guide Topics include: Climate & Gardening, Sunshine, Temperature, Humidity and Dew Point, Precipitation, and more.  It is a great way to make an important contribution that helps others.  By providing your daily observation, you help to fill in a piece of the weather puzzle that affects many people across your area and helps Master Gardener’s educate the public about weather and its impact on gardening.


University of Massachusetts

The University of Massachusetts, Amherst hosts the U.S. Department of Interior’s Northeast Climate Science Center (NECSC).  The Northeast Climate Science Center works with natural and cultural resource managers in the Northeast and Midwest regions to apply future climate scenarios to decision making and co-produce information, and tools for climate change adaptation.

The NECSC has an Academic Consortium comprised of seven (7) universities, including UMass Amherst, which provides outstanding expertise in climate science and natural and cultural resources management specific to the Northeast.

NECSC is part of a federal network of eight Climate Science Centers (CSCs) across the country created to work with natural and cultural resource managers to gather scientific information and build tools needed to help fish, wildlife, and ecosystems adapt to the impacts of climate change.

Find out more about their work in our region at .


The Nature Conservancy

The Nature Conservancy is a charitable environmental organization based in Arlington, VA dedicated to “conserve the lands and waters on which all life depends.” It is a valuable resource on many environmental topics and covers a broad range related to phenology.  Check out this link to read about phenology in general, find Citizen Science opportunities, and check out their blog posts.:


NPR Interviews

National Public Radio (NPR) has a variety of interesting and informative interviews related to phenology and how you can participate in it.  Here is a sample:

Project Budburst – A citizen science campaign collecting data about native plants.

Climate Scientists Enlisting Citizen Scientists – Scientists are actively seeking interested volunteers to provide observations of plants and flowers in their own backyard.  Here is the story at

More transcripts available by Googling NPR phenology or searching on NPR’s website,


Harvard Forest

Phenology is a topic of research and education at Harvard Forest, Harvard University’s 4,000 acre laboratory and classroom.  There is an abundance of phenology-related resources available for school age student education.  Here is a sample of a blog and article for K-12 students and teachers:

Here is an example of specifically teacher-focused phenology material:






©2021 Western Massachusetts Master Gardener Association